In August 1877, the American astronomer, Asaph Hall, discovered two moons orbiting Mars. He named them Deimos and Phobos, for the mythological sons of Ares, the Greek
counterpart of the Roman god, Mars. Phobos was the personification of panic. This
moon has a mass of 7.304 x 1014 slugs and orbits 3,700 miles above the surface of Mars.
Deimos was the personification of terror and dread. This moon has a mass of 1.0115 x
1014 slugs and orbits 12,470 miles above the surface of the red planet. Mars has a mass
of 4.397 x 1022 slugs and a radius of 2,106.1 miles. Determine the gravitational force
Mars exerts on Phobos.

Fluids at rest possess no flow energy. a)- true b)- false

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?

Most leaks in reciprocating air compressors can be detected and minimized by: (clo4) a)-detecting leakage areas using ultrasonic acoustic detector. b)-tightening joints and connections c)-replacing faulty equipment d)-all of the given options