A rectangular plate, whose streamwise dimension (or chord c) is 0.2 m and whose width (or span b) is 1.8 m, is mounted in a wind tunnel. The freestream velocity is 40 m/s. The density of the air is 1.2250 kg/m3, and the absolute viscosity is 1.7894 x 10-5 kg/m s. Plot (not sketch) the velocity profiles at x = 0.0 m, x = 0.05 m, x = 0.10 m, and x = 0.20 m. Calculate the chordwise distribution of the skin friction coefficient and the displacement thickness. What is the drag coefficient for the plate? Be sure to account for both sides of the plate.

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

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.

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?