A heat pump has COP = 4.0 and is used to deliver heat energy of 500 MJ to a house in one day.
(a) How much electrical energy is required to provide the work needed by the heat pump?
(b) Assume that this electrical energy is provided by a typical natural gas power plant. How much natural gas (in cf) needs to be burned at the plant?
(c) If the house had direct natural gas heating with 98% efficiency, how much natural gas would be needed to provide 500 MJ of heating?