Arotating machine of mass 100 kg sits on an elastic foundation comprised of a spring and a damper. the spring stiffness is 100 kn/m and the damping ratio is 0.25. the machine spins at 1900 rpm with an unbalance of 0.05 kg-m (a) determine the steady-state amplitude of vibration of the machine. (b) compute the force transmitted to the ground by the spring. (c) compute the force transmitted to the ground by the damper (d) compute the force transmitted to the ground by the spring and damper together

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?

Inadequate stores control is not an obstacle to effective work order system. (clo4) a)-true b)-false

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero