Download Physics_files/Unit 6 Review Part 3

Unit 6: Practice with Gravitational Potential Energy and
Kinetic Energy Equations and Conservation of Energy
1. What is the potential energy of a 3kg book sitting on a shelf 2.4m above the floor?
2. A backpack has potential energy of 120J. What is the mass of the backpack if it is
sitting on a table 1.2m above the floor.
3. How high above the ground does a 2kg bag of rice sit, that has 50J of potential
energy?
4. A 500kg car drives down the road at 20m/s. How much kinetic energy does it
possess?
5. A runner has a mass of 80kg. What is his speed if he has 4000J of kinetic energy?
6. A bowling ball has 1000J of kinetic energy and 8kg of mass. What is its velocity?
7. A ball sits on top of a pole 6m above the ground. Its mass is 3kg.’
a) What is its potential energy?
b) If dropped off the top of the pole, how much potential energy does it have
3m from the ground?
c) How much kinetic energy does it have at the same height?
d) How much kinetic energy does it have right before it hits the floor?
8. A cannon ball is shot from the cannon at a velocity of 40m/s straight up into the
air. Its mass is 3kg. How high will the ball fly?
9. A 200kg roller coaster car has 20,000J of potential energy when on top of the first
hill. At the bottom of that same hill its velocity is 13m/s.
a) What is its kinetic energy at the bottom of the hill?
b) How high was the hill it started from?
c) How much energy was transformed into heat and sound?
10. A basketball ball falls from a height of 4m. What is its speed before it hits the
floor?