Work done= force(N) x distance moved in the direction of force. (m)
Power= work done/ time taken.
Work done = 75N x 10m
= 750Nm/ 750J( Joules)* joules is the SI unit of work.
Power is the rate at which work is done. Suppose two men were carrying a heavy box, man A has a force of 10N , man B has a force of 10N and both carries the box of a distance 3m. Both have done the same work. But if suppose man A takes 2 seconds to carry the box while man B takes 3 seconds, their power needed are different.
Man A , power= 30J/ 2s which is 15 joules per second ( SI unit of power is “watts”)
Man B, power= 30J/ 3s which is 10 joules per second. MAN A HAS MORE POWER.
so, the work done for the wheelbarrow is 750J, divide it by the time taken( 30 seconds) 750J/30s= 25 J/s. <— this is the power needed.
