Extensive wind-tunnel and coast-down studies of a 2000-lb automobile reveal the aerodyna...

Extensive wind-tunnel and coast-down studies of a 2000-lb automobile reveal the aerodynamic drag force F_D and the total nonaerodynamic rolling resistance force F_R to vary with speed as shown in the plot. Determine (a) the power P required for steady speeds of 30 mi/hr and 60 mi/hr and (b) the time t and the distance s required for the car to coast down to a speed of 5 mi/hr from an initial speed of 60 mi/hr. Assume a straight, level road and no wind.