A parallel flow heat exchanger is used to transfer heat from hot water at 80oC, flowing at 5 L/min to cold water at 15oC which is flowing at a rate of 15 L/min. The overall heat transfer coefficient is 2000 W/m2oC and the area is 0.2m2. Calculate the heat transfer rate, the outlet temperature of the cold water.

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way