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.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.