)consider a tank connected to a supply line through a valve, similar to lecture example problem. the 1 m3 rigid tank contains ammonia, initially at 150 kpa and 25◦c. the tank is connected to a supply line with ammonia flowing at 500 kpa and 30◦c. the valve between the line and tank is opened and ammonia flows in until the tank is 10% liquid and 90% vapor (by volume) at 25◦c, at which time the valve is closed. determine: a. indicate initial state (1), final state (2), and inlet state (i) on t − v and p − v diagrams b. amount of mass that entered the tank [kg] c. heat transfer between tank and surroundings (magnitude and direction) during process [kj]

Awheel rotates without friction about a stationary horizontal axis at the center of the wheel. a constant tangential force equal to 82.0 n is applied to the rim of the wheel. the wheel has radius 0.150 m . starting from rest, the wheel has an angular speed of 12.8 rev/s after 3.88 s. what is the moment of inertia of the wheel?

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.

When does your body conduct current more readily?