A food department is kept at -12 oC by a refrigerator in an environment at 30 oC. The total heat gain to the food department is estimated to be 3300 kJ/h and the heat rejected in the condenser is 4800 kJ/h. Determine the power input to the compressor, in kW and the COP of the refrigerator

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length

The higher the astm grain size number, the finer the gran is. a)-true b)-false