Air is compressed by an adiabatic compressor from 100 kpa and 20°c to 1.8 mpa and 400°c. air enters the compressor through a 0.15-m2 opening with a velocity of 30 m/s. it exits through a 0.086-m2 opening. calculate the mass flow rate of air and the required power input. the constant pressure specific heat of air at the average temperature of 210°c = 483 k is cp = 1.026 kj/kg·k. the gas constant of air is r = 0.287 kpa·m3/kg·k.

If a small-diameter open glass tube is partially immersed in a vessel containing mercury, the surface of the mercury inside the tube will be a. lower than the mercury in the vessel, and shaped like the inside of a bowl. b. higher than the mercury in the vessel, and shaped like the inside of a bowl. c. lower than the mercury in the vessel, and shaped like the outside of an umbrella. d. higher than the mercury in the vessel, and shaped like the outside of an umbrella.