Name: Class: Date: _

ENERGY BASICS PACKETPacket Includes:

I. ObjectivesII. Energy Read ingIII. Energy NotesIV. Review Questions 1-7 & 11-17 (answer on separate sheet)V. Quiz Review

I. Unit Objectives:

1. Students will be able to define, correctly use, and provide examples of thefollowing terms:

EnergyKinetic energy (KE)Potential energy (PE)Mechanical energy (ME)Other types of Energy:

Thermal energyChemical energyElectrical energySound energyLight energyNuclear energy

Energy transfer / conversionConservation of energy

2. Students will be able to use a diagram or model of a moving object to describethe conversion of potential energy into kinetic energy and vice versa.

3. Students will be able to discuss different forms of energy and describe how theycan be converted from one form to another for use by humans (useable energy).

4. Students wi II be able to explain the energy conversion that takes place in thehuman body once food enters.

Student Energy Basics

Name' Closs' ,Dat.' _

II. Energy Basics Reading Read Energy Information on the next few poges & co~lete

defiritions in next section

Energy

Energy is the ability to do work. Work is done when a force moves an ob­ject over a distance. A flowing river has the ability to move a boal. A carmoving down the street can carry people from one place to another. There­fore. the river and the car possess some form of energy.

States of Energy

There are two basic slates of energy: potencial and kinetic.

1. Potential enefIDI is stored energy that an object has because of itsposition above some reference level or its chemical composition. Arock on top of a cliff has potential energy because of its positionabove ground level A lump of coal contains potential energy in itschemical bonds.

2. Kinetic eneFgy is energy that an object has because it is moving. Arock falling 0[[ a cliff has kinetic energy. The heat given off by aburning lump of coal is also a form of kinetic energy. The faster anobject moves, the more kinetic energy it has. Figw-e 11-1 shows ex­amples of polential and kinetic energy.

Potential energy may be changed into kinelic energy when an objectbegins 10 move. Water held back by a dam has polential energy bUI no ki­netic energy. Releasing the water and letting it flow changes its potentialenergy into kinelic energy.

Kinetic energy may also be changed into potential energy. When a ballis thrown straight up into the air, its kinetic energy of motion is changed

Figure I I - I. Some examples of potential energy and kinetic energy.

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ENERGY

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Student Energy Basics

Name: Class: Date: _

into potential energy as the ball rises higher above the ground. At the high­est point of the ball's flight, it is motionless and has only potential energy.As the ball falls back to the ground, the potential energy changes back intokinetic energy.

Forms of Energy

Both potential and kinetic energy exist in many forms. Meclumical energy, forexample, is the energy with which moving objects perform work. A hammer

.striking a nail, a jack lifting a car, and pedals turning the wheel of a bicycle areexamples of things using mechanical energy. Sound is a type of mechanicalenergy. Table 11-1 shows some examples of different forms of energy.

Chemical energy is energy stored in certain substances because of themake up of their chemical bonds. When these substances are burned, theenergy is released. Coal, oil, propane gas, and foods are examples of sub­stances that contain chemical energy.

Nuclear energy is the energy stored within the nucleus (center) of anatom. This energy can be released by joining small nuclei together or bysplitting large nuclei apart.

Heat energy is produced by the molecular motion of matter. All mat­ter contains heat energy. Rubbing your hands together, cellular respiration,or burning fuel oil in a home heating system can produce heat energy.

Electric energy is produced by the flow of electrons through a conduc­tor, such as a wire. Computers, light bulbs, and washing machines are alloperated with electric energy. A generator produces electric energy.

Light is a form of radiant energy that moves in waves. Light as a formof energy can be demonstrated by using a magnifying glass to burn a holein a leaf, or using a laser beam to burn a hole in a steel plate.

Conservation of Energy and Matter

The Law of Conservation of Energy states that energy can neither be cre­ated nor destroyed. However, energy can easily be transformed from one

Tobie JI-l. Different Forms of Energy

Form of Energy

Mechanical

Sound

Chemical

Nuclear

Heat

Electric

Light

Student Energy Basics

Example

Fan

Bell

Candle

Nuclear reactor

Toaster

Generator

Lamp (bulb)

Name: Class: ,Date: _

type of energy into one or more other types of energy. The Law of Conser­vation ofMatter states that matter can neither be created nor destroyed. En­ergy and matter are related in such a way that they are interchangeable.That is, the total amount of energy and matter in the universe is constant,and each can be converted into the other. In the sun, large amounts of mat­ter are being converted into light and heat energy. Scientists have been ableto change matter into energy in nuclear reactors and energy into matterunder special laboratory conditions.

Energy Transformations

Most of our daily activities involve the transformation of energy. For in­stance, when you take a bus to school each morning, chemical energy ingasoline is changed into mechanical energy that turns the wheels of thebus. At school, when the bell rings between classes, electric energy is trans­formed into sound energy. And at night, when you turn on a reading light,electric energy is changed into light energy. Figure 11-2 shows two commonenergy transformations.

Unusable Energy

Very often during the energy transformation process some heat energy isproduced that is not usable. For example, a car's motor is designed to changechemical energy in the gasoline into mechanical energy to move the car.However, a running motor eventually becomes hot, due to the burning offuel and the friction of the motor's moving parts rubbing against one an­other. In other words, some of the chemical energy is transformed into unus­able heat energy instead of mechanical energy.

A vacuum cleaner is another example of a machine producing unus­able energy. A vacuum cleaner contains a motor that transforms electric en­ergy into mechanical energy. Run a vacuum cleaner a few minutes and youcan feel that it gets warm. The electric energy entering the motor produces

Figure "-2. This hand-operated generator transforms mechanicalenergy into electrical energy, which is then transformed intolight energy.

__ Electrical energy __ Mechanical energy

Student Energy Basics

Name: Class: Date: _

Electrical

Energy in~

Vacuum cleaner

Frictionalheat energy1(unwanted)

• 1L..._M_e_ch_a_ni_ca_1-~

Energy out~

Figure JJ-3. Law of Conservation of Energy: "unusable" energy may bereleased during a transformation, but no energy is lost.

mechanical energy to operate the appliance and an unusable amount ofheat energy. This is illustrated in Figure 11-3.

Student Energy Basics

Name: Class: Date:, _

III. Energy Basics Notes

Complete the definitions and add more examples based on your reading (written orictures .

Term DefinitionEnergy

Kinetic energy(KE)KE = mv"

2

m = mass,v = velocity

Potential energy(PE)Gravitational PE =weight X height

Mechanicalenergy (ME)

ME = KE + PE

Exam les

Thermal energy The kinetic energy that all objects have dueto the movement of the particles that makethe object up. Depends on temperature andnumber of particles.

Example: Ice has less thermal energy thansteam.

------

Student Energy Basics

Name: Class: ,Date: _

Chemical energy , "

Electrical energy

~Sound energy Energy caused by objects vibration

Light energy tIII

Nuclear energy 'ILl~

Food Energy Chemical energy that comes from the foods Eat cereal, bodythat we eat. digests cereal, the

chemical energy fromUnit is calories (C) the cereal you eat is

transferred so you canFood is digested, chemical energy from food move.transferred so body can perform its e ~l- ~functions. ~)-+

<WI' & -

Unused enerQV is stored as fat.

Studenl Energy Basia

Name: Class: Date: _

Conservation ofenergy

Energy transfer

Student Energy Basics

Name: Class: ,Date: _

IV. Review Questions ultiple Choice 1-7 & Thinking 7 Analyzing 11-17

Answer the questions on the separate answer sheet given in class!

Multiple Choice

1. In the diagram below, a skier is about to start a slide (position A), skidown the hill (B), and stop at the bottom (C). At which position wouldthe skier have the most kinetic energy?

(l)A

(2) B

(3) C

Questions 2 and 3 refer to the following activity.

Angie stretches a large rubber band and then releases one of its ends. Therubber band snaps back to its original shape.

2. When the rubber band was stretched, it had

(l) potential energy (3) no energy

(2) kinetic energy (4) motion energy

3. As the rubber band was snapping back, it had

(1) potential energy (3) no energy

(2) kinetic energy (4) position energy

Student Energy Basics

Name: Class: Date: _

4. What type of energy transformation is represented in the diagram below?

(1) chemical energy to sound energy

(2) sound energy to chemical energy

(3) electric energy to sound energy

(4) sound energy to electric energy

5. Sound energy is transformed to electric energy in the

(1) telephone (2) radio (3) television (4) hair dryer

6. Which item transforms 100 % of the energy it receives into useful energy?

(1) window fan (3) battery-powered flashlight

(2) hair dryer (4) none of the items

7. While visiting an historic fort on vacation, John watched a demonstra­tion of the firing of a cannon. When the cannon fired, the sound trav­eled to John and he heard the sound with his ears. The medium for thesound waves was

(1) the cannon

(2) the air

Student Energy Basics

(3) John's ears

(4) none of the above

Name: Class: Date: _

Thinking and Analyzing

Questions 11 and 12 refer to the following activity. In an effort to break astrip of aluminum metal, Charles bent it back and forth many times. He wassurprised to notice the aluminum getting warm at the point of the bend.

11. This is an example of a transformation of

(1) heat energy to mechanical energy

(2) chemical energy to mechanical energy

(3) chemical energy to heat energy

(4) mechanical energy to heat energy

12. The heating of the metal strip in this case

(1) is a gain of energy

(2) is the creation of energy

(3) is the loss of energy

(4) is an unusable energy transformation

13. The diagram below represents three appliances that transform electricenergy into mechanical energy. The three items that best fit into boxesA, B, and C are the

I Item A I"""-Electrical~I Item B I ~ Mechanical

energy~ 'I ~ energy

I Iteme ~

(1) vacuum cleaner, table saw, fan

(2) television, fan, refrigerator

(3) radio, clock, fan

(4) lawn mower, hair dryer, generator

Student Energy Basics

Name' C1ass' ,DQt.' _

Questions 14-16 refer to the following diagram.

Ughting matches in a matchbook illustrates several different energy trans­formalions.

14. When you strike a match on the rough strip of a matchhook cover, youtransform

(1) mechanical energy to heat energy

(2) mechanical enetgy to chemical energy

(3) mechanical energy to electric energy

(4) heal energy to chemical energy

15. The burning malch involves the transformation of

(1) chemical energy to light and sound energy

(2) chemical energy to light and heat energy

(3) chemical energy to heat energy, only

(4) heat energy to light energy, only

16. The matches in the matchbook contain

(1) potential chemical energy

(2) potential light energy

(3) potential heat energy

(4) kinetic heat energy

17. What type of energy is produced by each of the items listed below?

a. toaster f. can opener

b. window fan g. hair dryer

c. vacuum cleaner h. lawn mower

d. leaf blower

e. telephone

Student Energy Basics

i. chain saw

j. stove

Name: Class: Date: _

V. Quiz Review

1. Tenns / Def1uitions: Write the correct tenn next to the def1uition

Tenn Defmition

the amount of work that an object can due because ofthe objects' kinetic and potential energy or the energywith which moving objects perform work

the abi lity to do work

moving energy - the energy of an object due to theobjects motion

The kinetic energy that all objects have due to themovement of the particles that make the object up.Depends on temperature and number of particles.

Produced by flow of electrons through a conductor suchas a wire

the stored energy that an object has due to its positionor chemical makeup.

Energy that moves in waves caused by the vibration ofelectrically charged particles and can travel through avacuum

Chemical energy that comes from the foods that we eat.

Energy stored in the nucleus of an atom, energy isreleased when nuclei join or split

Energy caused by objects vibrations that travel throughthe air

Energy stored in certai n substances because of the makeup of chemical bonds

A change from one form of energy to another

States that energy cannot be created or destroyed, butit can be transferred from one type if energy to othertypes of energy

Student Energy Basics

Nama: _______ Class:, 'tlat<>: _

II. Applyinlil Concepts

0, Explain the transfer/con.. "on of energy that t",,, place in the human body whenyou eat on ormge,

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b, Match the correct type of energy transform ation to the appropriate picture belowWrit. tht .f"U:r in tht spac. n.xt to tIM p;ctur.:

A. Chemicalto light

B, Electric to mechanical

C. Mechanicalto sound

_WStudent Energy Basics

Nama: _______ Class:, 'tlat<>: _

c, Label the diagram w~h the location of where the penduum has potent"l energy andkinetic energy

1

Student Energy Basics

1 3

~

2 _

3 _