A car of mass `m` is driven with acceleration `a` along a straight level road against a constant external resistive force R. When the velocity of the car V, the rate at which the engine of the car is doing work will be

Options

A. Rv
B. mav
C. (R+ma)v
D. (ma-R)v

Answer

C

Explanation

If F is the force exerted by the engine of the car,then
F-R=ma,
`therefore` F=(R+ma)
The power P=Fv=(R+ma)v.