Gravitational potential energy

Gravitational potential energy is the energy stored in an object due to its height above a gravitational field. Its calculated with $G.P.E. = mgh$.

Example

The mass is released from the top of the following system, if it looses $1\text{ MJ}$ what is its mass.

Find $h$

$$\begin{align} sin(13^{\circ}) &= \frac{h}{240}\\ 240 \times sin(13^{\circ}) &= h\\ h &= 53.988\\ &= 54.0\text{ m}\\ \end{align}$$

Find $m$

$$\begin{align} G.P.E. &= mgh\\ 1000000 &= m \times 9.8 \times 54.0\\ \frac{1000000}{9.8 \times 54.0} &= m\\ m &= 1889.645\\ &= 1890\text{ kg}\\ \end{align}$$