Power Energy Practice

Thursday, 12/5 – Power & Energy Practice

1. Power is the ______at which ______is done.

2. The equation for power is ______.

3. The unit for power is the ______which also called the ______.

4. Does an increase in power mean more work is being done? Circle one: yes or no

5. Explain your answer from #4. ______.

6. A person performs 90 J of work lifting a package onto a shelf. It takes 5 seconds to lift the box from the floor. How much power did the person generate?

G: E: S:

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7. If person generates 100 watts of power while pushing a lawn motor 10 meters in 120 seconds, how much work was done?

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8. Bart runs up a 2.91-meter high flight of stairs at a constant speed in 2.15 seconds. If Bart's mass is 65.9 kg, determine the work which he did and his power rating.

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9. On a recent adventure trip, Anita Break went rock-climbing. Anita was able to steadily lift her 80.0- kg body 20.0 meters in 100 seconds. Determine Anita 's power rating during this portion of the climb.

G: E: S:

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6. Calculate the total mechanical energy for the diagram above. a. 20,000 Joules b. 20,000 Watt c. 50,000 Joules d. 50,000 Watts

7. Calculate the kinetic energy for point C.

b. 20,000 Joules b. 30,000 Joules c. 35,000 Joules d. 50,000 Joules

8. Calculate the potential energy for point C.

c. 20,000 Joules b. 30,000 Joules c. 35,000 Joules d. 50,000 Joules

9. If the ski jumper from the diagram above was still moving when they reach point D what would their kinetic energy be?

d. 20,000 Joules b. 30,000 Joules c. 35,000 Joules d. 50,000 Joules

10. If the ski jumper from the diagram above was still moving when they reached point D what would their potential energy be?

e. 0 Joules b. 20,000 Joules c. 30,000 Joule d. 50,000 Joules