Serway & Jewett — The Kinetic Theory of Gases: Problem 10.

Your sister, who is a realtor, is quite interested in your studies in physics. Part of her job in selling properties involves being aware of the details of heating systems for the houses. She comes to you one day and says that a client told her the following: "If you measure the internal energy in the air in a house and then turn up the thermostat to a higher temperature, the internal energy of the air in the house is exactly the same as it was at the lower temperature." She finds this hard to believe, since you have added energy to the air by running the furnace. Help her to figure out if this statement is true or not.