# How much work does it take to raise a 26 kg  weight 3 m ?

Jun 7, 2016

There are (at least) two ways to answer this question. Both are included below. The answer, using either method, is $764.4$ $J$.

#### Explanation:

First method:

$W = F d$

Work = force times distance

The force of gravity on a mass $m$ is given by $F = m g$

Combining these equations:

$W = m g h = 26 \cdot 9.8 \cdot 3 = 764.4$ $J$

Second method:

The work done is equal to the change in gravitational potential energy:

${E}_{p} = m g h$ (hmm, look familiar?)

Both methods end up involving the same calculation and yield the same answer.