Question

What is the change is gravitational potential energy when a 1600ib elevator moves from street level to top of empire State Building 1250ft above street level.

Answer 1

Answer:

1600lb=7117N

1250ft=381m

They're asking you here for gravitational potential energy. That's equal to mgh. You've already got mg (force of gravity on the elevator) and h (height that the elevator reaches) so all you need to do is multiply the two numbers you had.

There’s only one thing here which might be potentially confusing, and that’s the significant digits. Both 7117 and 381 are only one sigfig each. Because of that, your answer can only be one sigfig. Some teachers would accept the answer you would automatically reach, others might insist that - due to sigfigs, the answer here would be 2,711,577J

Explanation: