An adiabatic tank with a volume of 1 m3 initially contains water at 6 mpa and 320◦c. water is withdrawn slowly from the tank until the pressure drops to 1.5 mpa. an electric resistance heater in the tank transfers energy which maintains the temperature at 320◦c. neglecting kinetic and potential energy effects, determine the amount of entropy produced in kj/k for the entire tank. assume that the exit properties are an average of the initial and final states.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Ajournal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. the bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. the bushing is 2.8 in long and supports a 700-lbf load. the journal speed is 900 rev/min. find the minimum oil film thickness and the maximum film pressure for both sae 20 and sae 20w-30 lubricants, for the tightest assembly if the operating film temperature is 160°f. a computer code is appropriate for solving this problem.

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