Consider the general aviation propeller-driven aircraft, with a weight of 2,900 lbs, in steady level flight through a constant horizontal headwind of 25 ft/s. (a) what is the expression for the power required to maintain steady level flight at an altitude of 14,000 ft? plot the power required to maintain steady level flight as a function of airspeed. what is the airspeed at which this required power is a minimum? what is the minimum value of the power required to maintain steady level flight? (b) if the elevator deflection is 3 degrees and the throttle setting is 80%, what are the possible flight conditions for which steady level flight can be maintained at an altitude of 14,000 ft? for each such flight condition, what are the airspeed and the angle of attack?

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

Water vapor initially at 10 bar and 400 °c is contained within a piston-cylinder assembly. the water lost heat to the surrounding according to isochoric (iso-volumetric) process until its temperature is 150 °c. the water is then condensed isothermally to saturated liquid. for the water as a system, calculate the work in kj/kg