Question

The mass of a car is 1000 kg. It starts from rest and attains a speed of 15 m s–1 in 3.0 seconds. Calculate (a) The average power of the engine. (b) The work done on the car by the engine.

Answer 1

Power=Work/Time=Force*Displacement/time
         =ma*s/t
    m=1000 kg;a=v-u/t=15-0/3=5 ms-2;t=3 s
    s=ut+1/2at2
      =1/2*5*9=22.5
    Power=1000*5*22.5/3
               =37500 Watt