static electricity “electrostatics”. “static”- not moving. electric charges that can be...

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Static Electricity “Electrostatics”

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Page 1: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Static ElectricityldquoElectrostaticsrdquo

bull ldquoStaticrdquo- not moving Electric charges that can be collected and held in one place

ndash Examples sparks on carpet balloon against hair lightning photocopier

ndash History ancient Greeks made little sparks when rubbing amber with fur (Greek word for amber ldquoelektronrdquo)

ndash Electric charge ldquoqrdquo is measured in Coulombs C One Coulomb is charge is a dangerously high charge An average lightning bolt has about 10 Coulombs of charge

bull Atomic Viewndash Proton in nucleus

bull Positive charge

bull q = + 16 x 10-19 Cndash Electron outside nucleus

bull Negative charge

bull q = - 16 x 10-19 Cndash Protons and Electrons have the same amount of

charge but a proton has much more massndash Neutron in nucleus has no chargendash Molecules

bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral

but if they have a net charge they are called

IONS

bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive

and negative charges

Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 2: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

bull ldquoStaticrdquo- not moving Electric charges that can be collected and held in one place

ndash Examples sparks on carpet balloon against hair lightning photocopier

ndash History ancient Greeks made little sparks when rubbing amber with fur (Greek word for amber ldquoelektronrdquo)

ndash Electric charge ldquoqrdquo is measured in Coulombs C One Coulomb is charge is a dangerously high charge An average lightning bolt has about 10 Coulombs of charge

bull Atomic Viewndash Proton in nucleus

bull Positive charge

bull q = + 16 x 10-19 Cndash Electron outside nucleus

bull Negative charge

bull q = - 16 x 10-19 Cndash Protons and Electrons have the same amount of

charge but a proton has much more massndash Neutron in nucleus has no chargendash Molecules

bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral

but if they have a net charge they are called

IONS

bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive

and negative charges

Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 3: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

bull Atomic Viewndash Proton in nucleus

bull Positive charge

bull q = + 16 x 10-19 Cndash Electron outside nucleus

bull Negative charge

bull q = - 16 x 10-19 Cndash Protons and Electrons have the same amount of

charge but a proton has much more massndash Neutron in nucleus has no chargendash Molecules

bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral

but if they have a net charge they are called

IONS

bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive

and negative charges

Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 4: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive

and negative charges

Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 5: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 6: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos

Hmmm+ + +- - -

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 7: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Robert Millikan

First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 8: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Materials

Conductorsbull Substances that have

easily moveable electric charges

bull Most familiar conductors are metals that have ldquofree electronsrdquo

bull Positive ions may also be mobile

ndash Insulatorsbull Charges cannot move

easilybull Examples plastic wood

glass

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 9: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Semiconductor used in computers

Conduction is an intermediate magnitude between a conductor and an insulator

Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 10: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called

ELECTROLYTIC behavior- )

ndash Air insulator or conductorbull Usually an insulator thankfullybull When strong forces are present electronrsquos can be

stripped from air molecules creating ionsbull example lightning

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 11: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

LightningAn electrical discharge between the clouds

and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

An electrical discharge between the clouds and the ground or between two clouds

As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING

The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)

We call that THUNDER

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 12: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

How much electrical charge is flowing through a lightning bolt

Typically around 10 Coulombs of charge

How many electrons each with a negative charge of 16 x 10-19 C does it take to have 10 C of charge

10 C 16 x 10-19 C =

625 x 1019 electrons

How many electrons are flowing in a 12 C lightning bolt

75 x 1019 electrons

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 13: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

The Earth is able to absorb much electrical charge

Touching a charged object to the Earth in order to discharge it is called

GROUNDING

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 14: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

bull Methods to electrically charge an object

ndash Conduction bull Direct contact will transfer

electrons such as touching your car door in the winter

bull Friction rubbing your feet against carpet hair against a balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 15: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object

near but not in contact with a neutral object

bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object

bull If provided a pathway the separated electrons will leave

bull The object is now positively charged

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 16: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

bull Electrostatics devicesndash Electroscope the

separation of metal leaves indicates the presence of static charge

ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome

ndash Electrophorus a device used to transfer electric charge

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 17: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Coulombrsquos Lawndash Calculates the magnitude

of the electric force between two charges

ndash Each charge experiences equal but opposite forces

k is a constant k = 9 x 109 Nm2C2

221

d

qqkF

(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 18: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation

221

d

mmGF

221

d

qqkF

Differences 1 Gravitational Force is based on MASS

Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force

The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively

small forceldquokrdquo is a huge number therefore electric force is a

relatively large force

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 19: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Both laws are INVERSE SQUARE LAWS

ldquoThe Force varies with the inverse of the distance squaredrdquo

At twice the distance d2 = 22 in denominator

= frac14 the Force

At three times the distance 32 in denominator

= 19 the Force

At half the distance (12)2 in denominator

= 4 times the Force

Now if one CHARGE q doubleshellip The Force doubles since they are directly related

221

d

qqkF

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 20: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Get a calculator and letrsquos practice onehellip

What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)

USE THE EXPONENT BUTTON

F = 9E9 32E-3 248E-6 divide 24E-3 2

F = 124000000 N

or for Quest 124E8

or 124e8

221

d

qqkF

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 21: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge

+-

+

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 22: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

Get a clicker and calculator Log in and get ready to answer some questions

1 Electric Charge is measured in

A Amps

B Volts

C Coulombs

D Farads

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 23: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

2 Opposite charges

A Attract

B Repel

C May attract or repel depending on their relative size

D Neither attract nor repel

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 24: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

3 Objects with a neutral charge are

A Attracted only by objects with a net positive charge

B Attracted only by objects with a net negative charge

C Not attracted by any kind of charge

D Attracted by objects with either positive or negative charge

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 25: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

The charge of one electron = - 16 x 10-19 C

4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28
Page 26: Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place –Examples: sparks on carpet, balloon

5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of

A 3

B 6

C 9

D 13

E 16

F 19

221

d

qqkF

  • Static Electricity ldquoElectrostaticsrdquo
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Robert Millikan
  • Slide 8
  • Slide 9
  • Slide 10
  • Lightning
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Get a calculator and letrsquos practice onehellip
  • RememberhellipForce is a VECTOR- it always points in a specific dir
  • Slide 23
  • Get a clicker and calculator Log in and get ready to answer s
  • Slide 25
  • Slide 26
  • The charge of one electron = - 16 x 10-19 C
  • Slide 28