A car of mass 1000kg moves at a constant speed of 20m/s along a horizontal road where the frictional force is 200N.calcutate the power developed by the engine.

Answer 1

Power is defined as work per unit of time. Work is force times the distance (as long as the force and distance are in the same distance).

As the force necessary to overcome friction is 200 N and the car travels 20 m in one second, the power developed by the engine is 200 N x 20 m/s = 4000 watts.