A 3000 kg cable car descends down a 200-m high hill. To control its speed, it has its own brakes as well as a 2000 kg counterweight on the other side of the hill. Assume that the rolling friction of both the cable car and the counterweight are negligible. First, calculate the braking force necessary for the car to descend at a constant speed. Then, calculate the car’s speed at the bottom of the hill if its brakes fail or are not engaged.