An automobile of mass 880 kg traveling down the slope of 25° is brought to a halt by applying the brakes, which locks the wheels. The coefficient of kinetic friction between the wheels and the road is 0.65. The car leaves skid marks 25 m long. (a) What is the force of friction between the car and the road? (b) What is the work done by friction on the car by bringing the car to a halt? (c) Using the conservation of total mechanical energy, find the speed of the automobile when the brakes were first applied.