A car of mass 1200 ~kg (together with the driver) is moving with a constant acceleration of 2 ~m / s ^2 . How much power does the engine generate at the instance, when the speed reaches 20 ~m / s ? (Assume that the coefficient of friction between the car and the road is 0.5 ).

Step-by-step solution

Power of engine overcomes friction and provides necessary acceleration to the car. Now friction, f= m g=0.5 1200 10=6000 ~N and accelerating force, F=m a=1200 2=2400 ~N So, total force produced by engine =F_T=8400 ~N We know that, the formula of power is P=F_T v Then, P=8400 20=168000 ~W