6-44Determine the COP of a refrigerator that removes heat from the food compartment at a rate of 5040 kJ/h for each kW of power it consumes. Also, determine the rate of heat rejection to the outside air.

With increases in magnification, which of the following occur? a. the field of view decreases. b. the ambient illumination decreases. c. the larger parts can be measured. d. the eyepiece must be raised.

Amixture of gases consists of 0.4 kg of oxygen, 0.7 kg of carbon dioxide, and 0.2 kg of helium this mixture is maintained at 100 kpa and 27°c. determine: (a) the apparent molecular weight of this mixture the volume it occupies (b) the partial volume of the oxygen, and (c) (d) the partial pressure of the helium

A200-mm wide strip 25 mm thick is fed through a rolling mill w/two powered rolls each of radius = 250 mm. the work thickness is to be reduced to 22 mm in one pass at a roll speed of 60 rev/min. the average flow stress of the work material, as it passes through the rolls is 175 mpa. the friction coefficient between rolls and work material is 0.20. 1, determine a)-if friction is sufficient for rolling.b)- if friction is sufficient: c)- calculate roll force i calculate roll torque. d)- calculate roll power.