A body of mass 2kg is initially at rest. A constant force of 5 N acts on it for 10 seconds. What is the average power of the force?

F - Force 

t - time

w - work

p - power

a - acceleration

F = ma  =>  a = F/m = 5/2 = 2.5 m/s²

u(intial velocity ) =0

using,  s= ut + 1/2 at²

s = 1/2 * 2.5 * 100 = 125 m

W(Work ) = Fs = 5*125 = 625 Joules

P(Power ) = W/t =  625/10 = 62.5 Joules/second = 62.5 Watt