Answers: 2
Physics, 22.06.2019 03:30
As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.
Answers: 3
Physics, 22.06.2019 11:00
Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide? kg • what must the total momentum of the system be after the train cars collide? kg •
Answers: 2
Physics, 23.06.2019 10:00
If the moon rises at a given location at 6: 00 p.m. today, about what time will it rise tomorrow night?
Answers: 1
A car of mass 500kg is travelling west along the highway and comes to a stop at a traffic light .Whe...