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

Dec 19, 2015

27.44 Joules

#### Explanation:

The formula for gravitational potential energy is $E = m g h$, 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 $g = 9.8 m {s}^{-} 2$.

$E = 7 \cdot 9.8 \cdot \frac{2}{5} = 27.44 J$

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