Question

A 5 kg sledge hammer is held over head (2 meters above the ground). What is the maximum amount of work it can do if it falls to the ground?

Answer 1

The maximum amount of work that the hammer can do while falling to the ground is equal to its variation of gravitational potential energy, which is given by:
$\Delta U = mg\Delta h$
where m is the mass of the hammer, g is the gravitational acceleration, h is the variation in altitude of the hammer.

Plugging the data of the problem inside the equation, we find
$W=mg\Delta h=(5 kg)(9.81 m/s^2)(2 m)=98.1 J$