Question

A man of mass 50 kg run up a flight of stairs having a rise of 5 M in 4 second what is the work done by the man what is the average power developed by man

Answer 1

Answer:

The work done by a man weighing 50kgs who climbs stairs having a rise of 5m in 4s is 2450J and the average power developed by the man is  612.5W

Explanation:

Step 1: Work done

            $W = F.S$ where W = work, F = Force and S = displacement.

            Here Force = weight exerted by the man

                            $F = mg$

                                $= 50 * 9.8$

                                $= 490 N$

             Thus,

                                $W = F.S\\W = (490N) * (5m)\\W = 2450J$

             Work done by the man = 2450J

Step 2: Average Power

           Power = Work / Time

           $P = W / t$

           Here time = 4s

           So,

           $P = W / t\\P = 2450 / 4\\P = 612.5W$

          Average power developed by the man = 612.5W