Ablowhard tests of lung capacity show that adults are able to exhale 1.5 liters of air through their mouths in as little as 1.0 second.1) if a person blows air at this rate through a drinking straw with a diameter of 0.74 cm , what is the speed of air in the straw? 2) if the air from the straw in part a is directed horizontally across the upper end of a second straw that is vertical, to what height does water rise in the vertical straw?

Identify the arrows that show the correct direction of heat transfer. 66°f 112°f 98°f

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.

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?