Question

A car is driven at a constant speed of 21 m/s (76km/h) down a road. The car's engine delivers 52 kW of power. Calculate the average force of friction that is resisting the motion of the car.

My thinking: Convert 52 kW to 5200 W. Force of friction = force applied because there is not a net force. Work = force x distance.

Answer 1

Since Work = Force x Distance,
Power = Force x Velocity
Average force = Power/Velocity
= (52,000 kg m^2/s^3)/(21 m/s) = 2476 N

Answer 2

Thank you!!