Question

A man raises a box of mass 50 kg to a height of 2 m in 20s, while another man raises the same box to the same height in 50s. Calculated:

1. the work done, and
2. the power developed by each man. Take g = 10 N kg^-1.

Answer 1

(i) Work done by each man = mgh

= 50 × 10 × 2

= 1000 J

(ii) Work done in first case = `w/t_1`

= `1000/20`

= 50 W

Work done in second case = `w/t_2`

= `1000/50`

= 20 W