Compressed air can be pumped underground into huge caverns as a form of energy storage. The volume of a cavern is 6.7 × 105 m3, and the pressure of the air in it is 8.3 × 106 Pa. Assume that air is a diatomic ideal gas whose internal energy U is given by . If one home uses 30.0 kW h of energy per day, how many homes could this internal energy serve for one day?