Question

How much work does it take to raise a `31 kg` weight `52 m`?

Answer 1

I got `15,797.6J~~15.8kJ`

Explanation:

You do work against gravity so you need to put in at least the same force as `mg` (the weight) to go for a displacement of `h=52m`;
so you get that the work will be:
`W=mgh=31*9.8*52=15,797.6J~~15.8kJ`