Name:______________________________________________________Date:_____________Period:___
Potential Energy, Kinetic Energy, and Conservation of Energy
A 650 kg roller coaster car starts from rest at the top of the first hill of its track and glides freely. Neglect
friction.
1. Using a metric ruler and the scale of 1.0 cm = 3.0 m., determine the height of each hill.
2. Calculate the gravitational potential energy at the top of each hill. Show all work including the
equation and substitutions with units.
3. Calculate the gravitational potential energy at the bottom of each hill. Show all work including the
equation and substitutions with units.
4. Determine the kinetic energy at the top of each hill.
5. Determine the kinetic energy at the bottom of each hill.
6. Calculate the speed of the car at the tops and bottoms of each hill.
Answer Key
Hill
1
2
3
Height Top
8.7 cm = 26.1 m
5.5 cm = 16.5 m
3.3 cm = 9.9 m
Height Bottom
3.3 cm = 9.9 m
2.5 cm = 7.5 m
0 cm = 0 m
Hill
1
2
3
PE Top(J)
169650
107250
64350
PE Bottom(J)
64350
48750
0
Hill
1
2
3
KE Top (J)
0
62400
105300
KE Bottom (J)
105300
120900
169650
Hill
1
2
3
Speed Top (m/s)
0
13.9
18.0
Speed Bottom (m/s)
18.0
19.3
22.8