An aluminum rectangular shaft has a cross section that is 1"tall with a 2" base and is 48" long. it is subjected to a torque of 2000 in.-lb. determine the angle of twist. use a shear modulus of 3.5x10^6 psi.

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet