Question

Meg lifted a box of books with a mass of 20 kg from the floor to a shelf 1.4 m off the ground. The applied force was equal to the weight of the box of books. How much work did Meg do?

Answer 1

The work done is equal to the potential energy, so:
Epg=mgh
Epg=20kg*9,81m/s²*1,4m
Epg=274,68J