PhysicsUnit I

Physics (from Greek φυσική (ἐπιστήμη), i.e. "knowledge, science of nature", from φύσις, physis, i.e. "nature”) the natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.

Physics

Mechanics-This is the study of mechanical movements of bodies, especially machines. This field facilitated the growth of industries which revolutionised the lifestyle.

Thermodynamics-This is the study about effects of variations in pressure, volume and temperature on physical systems. It is based on the analysis of integrated motion of the particles using statistics.

Electromagnetism- describes the interaction of charged particles with electric and magnetic fields. It can be divided into electrostatics, the study of interactions between charges at rest, and electrodynamics, the study of interactions between moving charges and radiation. 

Relativity- The special theory of relativity enjoys a relationship with electromagnetism and mechanics; that is, the principle of relativity and the principle of stationary action in mechanics.

Acoustics- Study of production, control, transmission, reception, and effects of sounds. 

Optics- Study of nature, properties of light, and optical instruments. Electricity- study of electric circuits, formation and laws and its application.Nuclear Physics- is the field of physics that studies the constituents and

interactions of atomic nuclei.

Branches of Physics

Algebraic TransformationTry to solve the following equations:

A. If

Find k, q, r and R

B. If

Find k, p ans z

Algebraic TransformationTry to solve the following equations:

C. If

Find VR, VL, and Vc

D. If

Find R, XL and XC

Direct Proportion- When we say that two things are directly proportional, it does not just mean that when one increases, so does the other.  It means that they both increase or decrease BY THE SAME FACTOR!  If one triples, the other triples too.  If one is divided by 5, so is the other. 

There is a more concise way to say this:  If two quantities are directly proportional, then their ratio is constant.

Relationship of the Variables

Direct Proportion

Relationship of the Variables

Student Height Shadow

  (meters) (meters)

1 1.44 .33

2 1.35 .29

3 1.38 .30

4 .85 .20

5 1.26 .31

6 1.61 .36

7 1.15 .24

8 1.29 .31

We can write this as an equation.  In the example we are currently working on, it would be:

H/S=k

where k is the constant value of the ratio. But then it is easy to rearrange this equation so that it looks like this:

H=kS

Inverse Proportion-When we say that two things are inversely proportional, it does not just mean that when one increases,  the other decreases.  It means that they change BY  FACTORS THAT ARE INVERSES!  If one triples, the other gets divided by three.  If one is divided by 5, the other must be multiplied by 5.

There is a more concise way to say this:  If two quantities are inversely proportional, then their product is constant.

Relationship of the Variables

Inverse Proportion

Relationship of the Variables

Trial Pressure Volume

# (atm) (mL)

1 1.0 30.1

2 1.4 21.9

3 1.8 17.7

4 2.2 14.6

5 2.6 11.8

6 3.0 9.8

7 3.4 8.8

8 3.8 8.2

In this case, the two quantities are P (pressure) and V (volume).  If we are saying that their product is constant, then:

PV=k

which can also be written as

V=k/P

Direct Square Proportion We already know that "is proportional to" means that the two things

have a constant ratio.  But now we are saying that first you have to square one of those two things and then the ratio is constant.  In equation form, it would be:

which is an equation that you learned in geometry class.  But you learned it in a re-arranged form:

Informally, we can say that if THING 1 is proportional to the square of THING 2, then when THING 2 increases by a given factor, THING 1 increases by the SQUARE  of that factor.  So for example, if you DOUBLE the radius of a circle, then the area gets multiplied by FOUR (because 22=4) and if you TRIPLE the radius of the circle, the area increases by a factor of NINE (because 32=9)

Relationship of the Variables

Direct Square Proportion

Relationship of the Variables

Cylinder Radius, r Volume,V

# (cm) (mL)

1 2.0 35.2

2 4.0 140.8

3 6.0 316.8

4 8.0 563.2

5 10.0 880

Inverse Square ProportionLike inverse proportions, we can start by saying that when one

goes up, the other goes down.  But this time,  the first quantity is inversely proportional to the SQUARE of the second quantity.  So when the second quantity changes by some factor, the first quantity changes by the INVERSE of the SQUARE of that factor. 

As usual, it's more concise when you say it mathematically. We'll write that the product of THING 1 and the SQUARE of THING 2 is a CONSTANT, or in this case, using 't' for thickness and 'r' for radius:

Relationship of the Variables

Inverse Square Proportion

Relationship of the Variables

The scientific Notation is also called the power-of-ten notation. Mx10 raise to nth power. M=(1-9)

To convert a large number to scientific notation, first count how many times the decimal place must be moved to the left to make the value one or less than 10, then multiply this number by 10 raised to the number of steps that you made.

Example: Mass of earth 60000000000000000000000006x10 raised to 24

To convert a small number to scientific notation, first count how many times the decimal place must be moved to the right to make the value one or less than 10, then multiply this number by 10 raised to the negative number of steps that you made.

Example: Mass of Electron 0.0000000000000000000000000000009119.1x10 raised to -31

Scientific Notation

Identifying SF

Rule 1: All nonzeros are considered significant (1-9).Ex: 2334.9=5SF

Rule 2: All zeros between significant digits or nonzero digits are SF.

Ex. 23006=5SF

Rule 3: All zeros to the left of the first significant numbers are NOT significant.

Ex: 0.00045=2SF

Significant Figures

Identifying SF

Rule 4: All zeros at the end/ at the right of the significant digits are considered significant if it comes with decimal point or over bar.

Ex: 31.30=4SF 300=1SF

Rule 5: Constants have infinite number of significant digits.

Ex: Π=infinite SF

Significant Figures

Addition and Subtraction of Significant Figures

The number of significant figures of the sum or difference is the same as in the number that has the fewest number of decimal point.

Ex: 23.36+52.3+15.224=90.9

Multiplication and Division of Significant Figures

The number of significant figures of the product or quotient is the same as in the number that has the fewest significant figures.

Ex: 13.5x9.4=127

Significant Figures

Fundamental Quantities The SI is founded on seven SI base units for

seven base quantities assumed to be mutually independent.

Properties of Matter

Fundamental Quantity

Name(unit)

Symbol(unit)

Length Meter m

Mass Kilogram kg

Time Second s

Temperature Kelvin K

Electric Charge Coulomb C

Amount of Substance mole mol

Luminous Intensity candela cd

Derived Quantities Other quantities, called derived quantities,

are defined in terms of the seven base quantities via a system of quantity equations. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units.

Properties of Matter

Properties of MatterDerived Quantity Name

(unit)Symbol(unit)

Area square meter m2

Volume cubic meter m3

speed, velocity meter per second m/s

Acceleration meter per second squared   m/s2

wave number reciprocal meter m-1

mass density kilogram per cubic meter kg/m3

specific volume cubic meter per kilogram m3/kg

current density ampere per square meter A/m2

magnetic field strength   ampere per meter A/m

amount-of-substance concentration mole per cubic meter mol/m3

luminance candela per square meter cd/m2

mass fraction kilogram per kilogram, which may be represented by the number 1 kg/kg = 1

Metric Prefixes

Prefix Symbol 10n Decimal English word

yotta Y  1024 1000000000000000000000000 septillion

zetta Z  1021 1000000000000000000000 sextillion

exa E  1018 1000000000000000000 quintillion

peta P  1015 1000000000000000 quadrillion

tera T  1012 1000000000000 trillion

giga G  109 1000000000 billion

mega M  106 1000000 million

Kilo k  103 1000 thousand

Hecto h  102 100 hundred

Deca da  101 10 ten

 100 1 one

Metric Prefixes

Prefix Symbol 10n Decimal English word[n 1]

 100 1 one

Deci d  10−1 0.1 tenth

Centi c  10−2 0.01 hundredth

Milli m  10−3 0.001 thousandth

Micro µ  10−6 0.000001 millionth

Nano n  10−9 0.000000001 billionth

Pico p  10−12 0.000000000001 trillionth

Femto f  10−15 0.000000000000001 quadrillionth

Atto a  10−18 0.000000000000000001 quintillionth

zepto z  10−21 0.000000000000000000001 sextillionth

yocto y  10−24  0.000000000000000000000001 septillionth

Scalar quantities are those that are described by magnitudes.

Ex: 600m

Vector quantities are expressed completely with magnitude and direction.

Ex: 600m, NE

Scalar and Vector

Parallelogram Method (tail to tail method)Step 1: Scale the given vectorsEx: 100km=10cmStep 2: Draw the scaled vectors. Both tails are in the

origin of the Cartesian plane.Step 3: Create parallelogram by drawing shadow of

each vectors, should be parallel and equal magnitude.Step 4: Draw the resultant vector, vector/line from tails

of the given vectors to the opposite point.Step 5: Measure the value of magnitude and direction

of the resultant vector by measuring again and use the scale for the magnitude. Use protractor for the direction.

Graphical Addition of Vector

Polygon Method (head to tail method)Step 1: Scale the given vectorsEx: 100km=10cmStep 2: Draw the first scaled vectors and draw small x-y

plane on the head of the vector.Step 3: Draw the second vector wherein its tail is

connected in the head of the first vector.Step 4: Draw the resultant vector, simply connect the

head of the second vector and tail of the first vector.Step 5: Measure the value of magnitude and direction

of the resultant vector by measuring again and use the scale for the magnitude. Use protractor for the direction.

Graphical Addition of Vector