Ahouse has an electric heating system that consists of a 300-w fan and an electric resistance heating element placed in a duct. air flows steadily through the duct at a rate of 0.66 kg/s and experiences a temperature rise of 7°c. the rate of heat loss from the air in the duct is estimated to be 300 w. determine the power rating of the electric resistance heating element. the constant pressure specific heat of air at room temperature is cp = 1.005 kj/kg·k.