Question

How much work does it take to raise a `7 kg` weight `2 m`?

Answer 1

Work done to raise a body to a height is stored as the gravitational potential energy of the body.

For gravitational potential energy, we have `U = mgh` where symbols carry their regular meanings.

In this case we have, `m = 7 kg, h = 2m` and `g = 9.81 ms^(-2)`.

Thus, `U = 7 * 2 * 9.81 = 137.34 J` which is equal to the work done to raise that object to that height.