Question

Determine the amount of potential energy of a 5-newton book that is moved to three different shelves on a bookcase. The height of each shelf is 1.0 meters, 1.5 meters, and 2.0 meters.

Answer 1

Potential energy is defined as

`U = mgh`

here we have

mg = weight = 5 N

now for different heights we can say

`h_1 = 1.0 m`

U = mgh

`U_1 = 5 * 1 = 5 J`

`h_2 = 1.5 N`

`U_2 = 5 * 1.5 = 7.5 J`

`h_3 = 2 m`

`U_3 = 5 * 2 = 10 N`

so potential energy in all three shells will be different and increases with height