The combined weight of the motorcycle and rider is 360 lb. The coefficient of kinetic fric...

The combined weight of the motorcycle and rider is 360 lb. The coefficient of kinetic friction between the tires and the road is μk = 0.8. The rider starts from rest, spinning the rear wheel. Neglect the horizontal force exerted on the front wheel by the road. In two seconds, the motorcycle moves 35 ft. What was the normal force between the rear wheel and the road?