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

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.

A boy of 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.

A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s.

(a) Compare: (i) the work done, (ii) the power developed by them.

(b) Calculate the (i) the work done, (ii) the power developed by each man.

Take g = 10N kg^-1.