1. A truck with a mass of 6800 kg (14,991 lb) has a brake system capable of exerting an instantaneous braking effort of 670 kW at 40 mph (17.88 m/s). While traveling at this speed, the driver sees in his path an obstacle that is 45 m (148 ft) away. Assuming the driver’s reaction time is three-quarters of a second, and assuming constant deceleration, will the truck stop before hitting the obstacle? (Answer: Yes; total stopping distance is 42.4 m [139 ft])
2. A car weighing 3220 lb goes from 60 mph to a stop in 180 ft. If the CG is 24 in. off the ground, the wheelbase is 120 in., and the car has a static weight^istribution of 50/50, calculate the vertical forces on the front and rear axles during the stop. (Answer: 2040 lb front, 1180 lb rear)
3. For the drum brake in Section 9.5.2, determine the maximum coefficient of friction between the shoe and drum before the shoe becomes self-locking. (Answer: 1.64)
4. Derive the equations for the application force and torque capacity of a disc brake as functions of application force and pressure for the case of uniform pressure. (Hint: Refer to Chapter 6 for the torque capacity of a clutch with uniform pressure.)