1)Determine the work available in a 3.1 -kg block of copper at 490 K if the surroundings are at 300 K. (relates to a theorem that states how much energy is unavailable to do work)
2) An ideal air conditioner keeps the temperature inside a room at 23 C when the outside temperature is 39 C. If 3.0 kW of power enters a room through the windows in the form of direct radiation from the Sun, how much electrical power would be saved if the windows were shaded so only 900 W came through them?