In the context of mechanical systems, what does the term efficiency mean? O A. the factor by which a machine multiplies a force OB the ratio of a machine's power to the force of its input Ос. the rate at which a machine performis work OD the rate at which a machine consumes energy OE. the ratio of the work output of a machine to the work input

What precautions should you take to prevent injuries when dealing with heavy loads?

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit. explain why the pneumatic piston stumbles when it hits an obstacle.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?