The ducts of an air heating system pass through an unheated area. as a result of heat losses, the temperature of the air in the duct drops by 4°c. if the mass flow rate of air is 125 kg/min, determine the rate of heat loss from the air to the cold environment. the constant pressure specific heat of air at room temperature is cp = 1.005 kj/kg·k.

For each of the following process: a) sketch the p-v diagram, b)sketch t-s diagram, c) sketch t-v diagram, d) sketch the boundary work on one of the diagrams (a, b or c) and e) sketch the reversible heat transfer on one of the diagrams (a, b or c): 1- isobaric process from compressed liquid to superheated vapor 2- isothermal process from compressed liquid to superheated vapor 3- isentropic process from compressed liquid to superheated vapor