Refrigerant R-134a enters an evaporator at -4C and a quality of 0.2. The refrigerant flows through a circular pipe of constant diameter at a velocity of 7 m/s and steady mass flow rate of 0.1 kg/s. If it leaves the evaporator as saturated vapor at -4C, determine a) the diameter of the pipe, and b) the velocity of the refrigerant at the outlet. D = cm V2= m/s