A monoplane weighing 2000 lb has a span of 38 ft. What is the power required to overcome the induced drag when the airplane is at 10000 ft altitude with a velocity of 80 mph?

The resultant of the pressure and wall shear forces acting on a body is measured to be 430 N, making 30° with the direction of flow. Determine the drag and the lift forces acting on the body.

A 3-m-high, 6-m-wide rectangular advertisement panel is attached to a 6-m-wide, 0.15-m-high rectangular concrete block (density = 2500kg/m') by two 5-cm-diameter, 6-m-high (exposed part) poles as shown in the figure. If the sign is to withstand 180 km/h winds from any direction, determine (a) the maximum drag force on the panel, (b) the drag force acting on the poles, and • (C) the minimum length L of the concrete block for the panel to resist the winds. Note: Take the density of air to be 1.25kg/m. 6 m 3 m 6 m Concrete 0.15 m 6 m

Define the frontal area of a body subjected to external flow. When is it appropriate to use the frontal area in drag and lift calculations?

An airplane is consuming fuel at a rate of 7 gal/ min when cruising at a constant altitude of 10,000 ft at constant speed. Assuming the drag coefficient and the engine efficiency to remain the same, determine the rate of fuel consumption at an altitude of 30,000 ft at the same speed.

Large commercial airplanes cruise at high altitudes (up to about 40,000 ft) to save fuel. Discuss how flying at high altitudes reduces drag and saves fuel. Also discuss why small planes fly at relatively low altitudes.

Air is flowing past a spherical ball. Is the lift exerted on the ball zero or nonzero? Answer the same question if the ball is spinning.

To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is to be reduced. Determine the amount of fuel and money saved per year as a result of reducing the frontal area from 17 to 14 ft2. Assume the car is driven 10,000 mi a year at an average speed of 55 mi/h. Take the density and price of gasoline to be 50 lbm/ft3 and $3.10/gal, respectively; the density of air to be 0.075 lbm/ft3; the heating value of gasoline to be 20,000 Btu/lbm; and the overall efficiency of the engine to be 30%.