An automobile has been designed to maintain a constant speed of 55 mph on a +5% grade. The weight of the vehicle when fully loaded is 6000 lbs. What is the total resistance in still air of this vehicle? What would be the resistance on a level road? What horsepower must be delivered to the wheels on the grade? If the efficiency is 80%, what must be the rated horsepower of the motor? Use:
R = 0.01T + 0.0001Tv + 0.0028CAv2
where
R = resistance (lb)
T = weight (lb)
v = velocity (mph)
C = air resistance parameter = 0.040
A = maximum cross section = 100 ft2.
Discuss your results.