Name: Deuce BЈ Тасла BJ More Conservation of Energy Period: 3rd Problem 1: A car 1500 kg is traveling at 30 m/s. The driver slams on the breaks, and all the car's Mechanical Kinetic Energy is transferred into thermal energy in the brakes. How much thermal energy do the breaks gain? If the brakes have a mass of 5 kg and a specific heat of 1500 J/kg * C, how much do the brakes temperature increase by?. *

In 1990 Walter Arfeuille of Belgium lifted a 281.5-kg object through a distance of 17.1 cm using only his teeth. (a) How much work did Arfeuille do on the object? (b) What magnitude force did he exert on the object during the lift, assuming the force was constant?

A certain steel railroad rails 13 yd in length and weighs 70.0 lb/yd How much thermal energy is required to increase the length of such a rail by 3.0 mm? .Note: Assume the steel has the same specific heal as iron.

A 4ton air conditioner removes 5.60107J (48,000 British thermal units) from a cold environment in 1.00 h. (a) What energy input in joules is necessary to do this if the air conditioner has an energy efficiency rating (EER) of 12.0? (b) What is the cost of doing this if the work costs 10.0 cents per 3.60106J (one kilowatt—hour)? (c) Discuss whether this cost seems realistic. Note that the energy efficiency rating (EER) of an air conditioner or refrigerator is defined to be the number of British thermal units of heat transfer from a cold environment per hour divided by the watts of power input.