An ox can apply a maximum force of 1000N. It is taking part in a cart race and is able to pull the cart at a constant speed of 30ms^-1 while making its best effort. Calculate the power developed by the ox.

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

A boy weighing 350 N climbs up 30 steps, each 20 cm high in 1 minute.

Calculate:

(i) the work done, and

(ii) the power spent.

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.