Week 27 CA Review

Chapter 3- Energy

Chapter 10 Energy Sources

Chapter 16- Gas Laws

• 1. _____________ is the ability to cause change.

• 2. Energy is measured in units called ________________.

• 3. Potential energy is energy that is ______________ and due to position.

• 4. Potential energy is energy waiting to be _______________.

• 5. Objects that are NOT in _____________ have potential energy.

• 6. What is the formula for potential energy? ___________________

Energy

stored

released

motion

PE= mgh

Joules

• 7. A boulder with a mass of 55kg is sitting on the side of a cliff 30 m high. Calculate the gravitational potential energy of the boulder.

PE = mgh

PE=?

m=55 kg

g=9.8 m/s2

h= 30 m

PE = 55 * 9.8 * 30

16,170 J = 55 * 9.8 * 30

• 8. What distance is a vase from the floor if the vase contains 280 J of potential energy and has a mass of 4 kg.

PE = mgh

PE= 280 J

m=4 kg

g=9.8 m/s2

h= ?

280 = 4 * 9.8 * h

280 = 39.2 * h

280 = 39.2 * h

39.2 39.2

280 = h

39.2

7.14 m = h

• 9. A flower pot is sitting on a windowsill 15 m above the ground. Find the mass of the flower pot if it contains 2,300 J of potential energy.

PE = mgh

PE= 2300 J

m= ?

g=9.8 m/s2

h= 15 m

2300 = m * 9.8 * 15

2300 = m * 147

2300 = m * 147

147 147

2300 = m

147

15.65 kg = m

• 10. Energy in the form of _____________ is called kinetic energy.

• 11. What is the formula for kinetic energy?

motion

KE = mv2

2

• 12. A boy on a dirt bike passes by at a speed of 20 m/s. His mass is 45 kg. What is his kinetic energy?

KE = mv2

2

KE= ?

m= 45 kg

v= 20 m/s

KE = 45 * 202

2

KE = 18000

2

KE = 9000 J

• 13. How fast is the toy truck rolling if it contains 600 J of kinetic energy and has a mass of 6 kg?

KE = mv2

2

KE= 600 J

m= 6 kg

v= ?

600 = 6v2

2600 = 3v2

600 = 3v2

3 3600 = v2

3200 = v2

√200 = √ v2

√200 = v

14.14 m/s= v

• 14. Find the mass of a dog that is running at a speed of 3m/s if the dog has 600 J of kinetic energy.

KE = mv2

2

KE= 600 J

m= ?

v= 3 m/s

600 = m32

2600 = m9

2

600 = m* 4.5

600 = m* 4.5

4.5 4.5

600 = m

4.5133.33 kg = m

• 15. Law of Conservation of Energy states: Energy can not be ____________ or _____________ it can only be converted from one form of energy to another.

• 16. Law of Conservation of Energy states: The total amount of energy in the universe remains _____________.

created

destroyed

constant

• 17. _________________ converts some mechanical energy to thermal (heat) energy.

• Example: Rubbing your hands together.

Friction

• A. light energy thermal energy• B. solar energy chemical potential energy• C. elastic potential energy kinetic energy• D. potential energy kinetic energy• E. chemical potential energy kinetic energy

B E C D A

Directions: Write PE (potential energy) or KE (kinetic energy) next to the corresponding statement.

22. _________ Person running

23._________ Piece of cake

24. _________ Apple in a tree

25. _________ Plants

26. _________ Bicyclist going down a hill

27. _________ Spider crawling up the wall

KE

PE

PE

PE

KE

KE

28.Directions: Determine the position where the potential energy is the GREATEST in the pictures below and label that position “Greatest PE”

A

B CB

A

Greatest PE

Greatest PEGreatest PE

29. Directions: Determine the position where the kinetic energy is the GREATEST in the pictures below and label that position “Greatest KE”

A

B C

Greatest KE Greatest KE Greatest KE

30. Explain what happens to the amount of kinetic energy as the potential energy increases

As the amount of potential energy increases the amount of kinetic energy increases

• 1. Energy sources can be _______________ or ________________.

• 2. Fossil fuels are formed from the decaying remains of _____________ and _____________. The supply of fossil fuels is diminishing so they must be used wisely.

• 3. Acid rain is due to the burning of ____________ fuels.• 4. Types of fossil fuels include:

– A. _________________________– B. _________________________– C. _________________________

• 5. _______________ resources are resources that are replaced by natural processes nearly as quickly as they are used.

renewablenonrenewable

plants animals

fossil

petroleumnatural gascoal

renewable

• 6. _______________ resources are resources that can NOT be replaced by natural processes as quickly as they are used.

• 7. Directions: Write “RR” (renewable resource) or “NR” (nonrenewable resource) next to the energy source below.

• _____ windmill• ____ petroleum • _____ solar energy• ______ coal• _____ tidal energy • _____ hydroelectricity • _____ natural gas• _____ geothermal energy

nonrenewable

RR

RRNR

RRRR

NRRR

NR

8. Nuclear energy power plants produce radioactive by-products called _____________ waste that is very hazardous to the environment and people.

Nuclear

• 1. List the 4 phases of matter:– ______________________________

• 2. Charles’ law states (Pressure is constant): – As the temperature of a gas increases, the

volume _____________.– As the temperature of a gas decreases, the

volume ____________.

solid, liquid, gas, plasma

increases

decreases

High temperatureHigh volume

Low temperatureLow volume

• 3. Explain why the size the of the balloon changes when the temperature increases? Hint- Think about the speed and movement of the gas particles when the temperature increases.

Heat causes gases to expand. Gas particles speed up and hit the walls of the balloon more frequently expansion

• 4. Explain why the size of the balloon changes when the temperature decreases? Hint- Think about the speed and the movement of the gas particles when the temperature decreases.

Gas particles slow down and hit the walls of the balloon less frequently shrinking of balloon_

• 5. Boyle’s Law states (Temperature is constant): – As the volume of the container increases the

pressure of the gas ________________ – As the volume of the container decreases the

pressure of the gas ________________ increases

decreases

6. Explain why the pressure inside of the apparatus is high when the volume is low? Hint- Think about the amount of space that the gas particles have to move around. Less volume means the gas particles have less space to move around more pressure

7. Explain why the pressure inside of the apparatus is low when the volume is high? Hint- Think about the amount of space that the gas particles have to move around. More volume means the gas particles have more space to move around More volume means the gas particles have more space to move around less pressure