A boy of mass 40 kg runs up a flight of 15 steps each 15 cm high in 10 *. Find: (i) the work done and

Question 1

A boy of mass 40 kg runs up a flight of 15 steps each 15 cm high in 10 *. Find:

(i) the work done and

(ii) the power developed by him

Take g = 10 N kg-1

Question 2

Force of gravity on boy

F= mg = 40 × 10 = 400N

Total distance covered in 15 steps ,

Work done by the boy in climbing = Force x distance moved in direction of force

Work, W = F × * = 400 × 2.25 = 900J

Power developed = work done/time takrn = 900J/10s = 90W