Physics · Work, Power & Energy
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What is the change in gravitational potential energy when a 7000 N elevator moves from street level to the top of a building 300 m above street level?
- A
2100 J
- B
21000 J
- C
210000 J
- D
2.1 x 106 J
- E
210 J
Change in potential energy = work done in raising the elevator = weight force * distance moved = mg * h
=(7000 N * 300 m)
= 2100000=2.1 x 106 joules
Since it is a numerical so it could have only one answer.
This value is too low for the given force and height. Double-check the calculation.
This is an underestimation of the potential energy change. Review how potential energy is calculated.
This is closer, but still incorrect. Remember to multiply the force by the displacement.
Correct! The potential energy change is calculated as the product of the force (weight) and the height.
This value is much too low. Check your calculations and the units used.
Tagged under Physics · Work, Power & Energy · 2012