Question

A car is driving at constant speed down the road.  The mass of the car is 1350 kg and the coefficient of rolling friction is 0.18?  How much engine force is needed to keep the car moving? [Hint:  Draw a free body diagram]

Answer 1

The force is equal to the force of rolling resistance:

$$F=f=\mu mg=0.18 ·1350·9.8=2381\text{ N}.$$