Aheat pump with a cop of 2.8 is used to heat an air-tight house. when running, the heat pump consumes 5 kw of power. if the temperature in the house is 7°c when the heat pump is turned on, how long will it take for the heat pump to raise the temperature of the house to 22°c? is this answer realistic or optimistic? explain. assume the entire mass within the house (air, furniture, etc.) is equivalent to 1500 kg of air.