Question

A man of mass 50kg runs up a flight of stairs having a rise of 5m,in 4s.
1)What is the work done by the man?
2)What is the average power developed by the man?

Answer 1

Work done = Force × displacement

Force due to the man = mg = 50kg × 10m/s² = 500N

displacement = 5 meters

Work = 500 × 5 = 2500 Joules

Power developed

Power = Work ÷ time
           = 2500 ÷ 4
           = 625 Watts