Question

What is the gravitational potential energy of a `7 kg` object on a shelf `2/5 m` high?

Answer 1

27.44 Joules

Explanation:

The formula for gravitational potential energy is `E=mgh`, where `m` is the mass of an object, `g` is the gravitational field strength it experiences and `h` is its height above a known level.

In this calculation I'm assuming the gravitational field strength `g=9.8 ms^-2`.

`E=7*9.8*2/5=27.44 J`

This is the amount of work that would have to be done to lift the object from ground level onto the shelf.