A2650-lb car is traveling at sea level at a constant speed. its engine is running at 4500 rev/min and is producing 175 ft-lb of torque. it has a drivetrain efficiency of 90%, a drive axle slippage of 2%, 15- inch–radius wheels, and an overall gear reduction ratio of 3 to 1. if the car's frontal area is 21.5 ft 2 , what is its drag coefficient?