The power of a motor is 40 kW. At what speed can the motor raise a load of 20,000 N?

Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10ms^-1. Calculate the power exerted.

It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s.

Compare the

(i) work done and

(ii) power developed by the persons A and B.

A boy weighing 40 kgf climbs up a stair of 30 steps, each 20 cm high in 4 minutes and a girl weighing 30 kgf does the same in 3 minutes.

Compare :

(i) the work done by them, and

(ii) the power developed by them. Take g = 10 N kg^-1.