Question

A 0.25 kg book falls off a 2 m shelf on to a 0.5 m chair. What was the change in GPE?

Answer 1

The equation of GPE is mgH, where m is mass, g is gravitational acceleration, and H is the height.

If we're solving for the change in GPE, then:

∆
`U_(g)` = mg∆H

Input our given values for m and g:

∆
`U_(g)` = 0.25 * 9.80 * ∆H

The book falls from 2 meters high to 0.5 meters high, so:

∆
`U_(g)` = 0.25 * 9.80 * (2.0 - 0.5)

∆
`U_(g)` = 0.25 * 9.80 * 1.5

∆
`U_(g)` = 3.675 (J)

Adjust for significant figures:

∆
`U_(g)` = 3.7 (J)

The change in gravitational potential energy was 3.7 (J)

If you have any questions on anything I did to get to the answer, just ask!

- breezyツ