Work, Power, and Energy Short Answer Problems

1. What happens to the energy of a body if its vertical velocity is quadrupled? What energies are affected?

2. How much more work will be required to be done in question #1 if the above change took place? Also, how will the power required be affected?

3. Describe the factors that affect work & explain how they are inter-related -

4. What variable(s) affect the power that must be developed by the motor used to operate a ski lift (only in terms of the concepts that have been discussed in class so far this year)? How is(are) the(these) variable(s) inter-related?

5. If the work of a hammer is to be halved, what two separate adjustments might one make to accomplish this change? (You may not physically alter the hammer)

6. State the form(s) of energy (all possible types) that exist in the following AND EXPLAIN WHY!

A) A can of compressed air -

B) A car being driven up Montage Mountain -

C) A ball used in a game of handball -

D) A ball sliding down an inclined surface -

E) A trip to California in a jet -

7. An pulley system is used to lift a heavy boat onto its trailer. The force needed to lift the boat is much smaller in magnitude than the weight being lifted. Does this mean that less work is being done than if the object had been lifted directly? EXPLAIN IN DETAIL!

8. CONTRAST AND COMPARE Potential energy and work

9. What variable(s) affect the power that must be developed by the motor used to operate an escalator that is to be installed in a new shopping mall? (only in terms of the concepts that have been discussed in class so far this year)? How is(are) the(these) variable(s) inter-related?

10. Compare and contrast potential energy and kinetic energy, using formulas and diagrams.

11. Compare and contrast the effect that "v" and "t" have on the power developed by the engine of a car.

12. Explain the significance of the unit "kgm²/sec²".

13. An automobile jack is used to lift a heavy car be means of a force that is much smaller in magnitude than the weight being lifted? Does this mean that less work is being done than if the object had been lifted directly? Explain.

14. In uniform circular motion we studied the concept of centripetal force. Does centripetal force perform any work? Explain.

15. A body moving horizontally with a constant velocity on a horizontal surface starts up a frictionless surface inclined at 40 degrees. Derive a relationship that will express how far it will move up the incline before coming to rest.