Question

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

Answer 1

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=Fd`

Work = force times distance

The force of gravity on a mass `m` is given by `F=mg`

Combining these equations:

`W=mgh=26*9.8*3=764.4` `J`

Second method:

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

`E_p=mgh` (hmm, look familiar?)

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