# What is the gravitational potential energy of a  9 kg object on a shelf  4 m  high?

Jun 3, 2016

gravitational potential energy: $400 J$

#### Explanation:

The gravitational potential energy of an object can be calculated with the formula:

$\textcolor{b l u e}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{{E}_{g} = m g h} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

$\underline{\text{where}}$:
${E}_{g} =$gravitational potential energy
$m =$mass
$g =$acceleration due to gravity
$h =$height

To find the gravitational potential energy of the object, substitute your known values into the formula.

${E}_{g} = m g h$

${E}_{g} = \left(9 k g\right) \left(9.81 \frac{m}{s} ^ 2\right) \left(4 m\right)$

${E}_{g} = 353.16 J$

Rounding off to one significant digit,

${E}_{g} \approx \textcolor{g r e e n}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} 400 J \textcolor{w h i t e}{\frac{a}{a}} |}}}$