1. Use this diagram to answer the following questions. The balls are
not moving at either position, and are made of the same
material.
1. Where does the hollow, white ball have
most GPE?
2. Where does the hollow, white ball have
the least GPE?
3. Where does the solid, black ball have most
GPE?
4. Where does the solid, black ball have least
GPE?
5. Do the two balls at the top of the hill have
the same amount of GPE?
6. Do the two balls at the bottom of the hill
have the same amount of GPE?
A
B
Surface of the Earth
A
B
A
B
No
Yes, zero
Joules

2. ReviewReview
GPEGPE
What factors affect GPE:What factors affect GPE:
MassMass
HeightHeight
GPE = mghGPE = mgh

3. Changing the Height
0
1
2
3
4
5
6
0 0.2 0.4 0.6 0.8 1 1.2
Height (m)
PE(J)
GPE

4. Changing the Mass
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 0.1 0.2 0.3 0.4 0.5 0.6
Mass (kg)
PE(J) GPE

5. Kinetic EnergyKinetic Energy
 Energy of objects inEnergy of objects in
motionmotion
 Affected by:Affected by:
 MassMass
SpeedSpeed

6. Kinetic EnergyKinetic Energy
 KE = 1/2mvKE = 1/2mv22
 KE = kinetic energy, (J)KE = kinetic energy, (J)
 m = mass (kg)m = mass (kg)
 v = velocity (speed) (m/s)v = velocity (speed) (m/s)

7. • What is the kinetic energy of a 44 kg cheetah running at
31 m/s?
Pg. 395

8. • What is the kinetic energy of a 44 kg cheetah running at
31 m/s?
Pg. 395