A man spends 7.4 kJ energy in displacing a body by 74 m in the direction in which he applies force, in 2.5 s.

Calculate:

(i) the force applied and

(ii) the power spent (in H.P) by the man.

A weight lifter lifted a load of 200 kgf to a height of 2.5 m in 5 s.

Calculate:

(i) the work done, and

(ii) the power developed by him.

Take g = 10Nkg^-1

An electric heater of power 3 kW is used for 10 h. How much energy does it consume? Express your answer in

(i) kWh

(ii) joule.

A water pump raises 50 litres of water through a height of 25m in 5s. Calculate the power of the pump used (assuming 100% efficiency).

(Take g = 10 N kg^-1 and density of water = 1000 kg m^-3).