The brakes on a truck can overheat and catch on fire if the truck goes down a long steep hill without shifting into a lower gear.
(a) Explain why this happens in terms of energy and power.
(b) Would it matter if the same elevation change was made going down a steep hill or a gradual hill? Explain your reasoning.
(c) Why does shifting into a lower gear help?
(d) Calculate the thermal energy dissipated from the brakes in an 8000-kg truck that descends a 12° hill. The truck begins braking when its speed 95 km/h is and slows to a speed 35 km/h of in a distance of 0.36 km measured along the road.