Consider a house that has a floor space of 15m x 12m and an average height of 2.7 m at 150m elevation where the standard atmospheric pressure is 84.1 kPa (shown in figure below). Initially the house is at a uniform temperature of 10°C. Now the electric heater is turned on, and the heater runs until the air temperature in the house rises to an average value of 21°C. Determine the amount of energy transferred to the air assuming (a) the house is air-tight and thus no air escapes during the heating process and (b) some air escapes through the cracks as the heated air in the house expands at constant pressure. Also determine the cost of this heat for each case if the cost of electricity in that area is $0.080/kWh
Consider a house that has a floor space of 15m x 12m and an average height of 2.7 m at 150m elevation where the standard atmospheric pressure is 84.1 kPa (shown in figure below). Initially the house is at a uniform temperature of 10°C. Now the electric heater is turned on, and the heater runs until the air temperature in the house rises to an average value of 21°C. Determine the amount of energy transferred to the air assuming (a) the house is air-tight and thus no air escapes during the heating process and (b) some air escapes through the cracks as the heated air in the house expands at constant pressure. Also determine the cost of this heat for each case if the cost of electricity in that area is $0.080/kWh
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