posted by Anonymous .
A car with a mass of 890 kg travels at a speed of 20.0 m/s. Seeing that the road ahead is blocked by a rock slide, the driver applies the brakes, stopping the car. The work of stopping the car becomes thermal energy of the car’s four disk brake rotors; in other words, all of the energy goes into the brake rotors. Each rotor has a mass of 6.5 kg. The rotors are made of a metal with a specific heat capacity of 420 J/(kg °C).
After the car is stopped, how much has the temperature of its brake rotors increased? Give your answer in degrees Celsius. Assume that all four brake rotors receive the same amount of heat.