Problem 6. Jim Hall's Chaparral 2F sports-racing cars in the 1960's pioneered the use of airfoils mounted above the rear suspension to enhance stability and improve breaking performance. The airfoil had an effective width (or span) of b = 6.0 ft and chord length of c = 1.0 ft. The angle of attack varied between a = 0° and a = -12°. The shape was similar to that of a NACA 23015 conventional airfoil. For a car speed of U = 90 mph on a calm day and a = -12°, estimate (a) the downward force and (b) the increase in breaking force, AFB. produced by the airfoil accounting for "induced drag" for the finite wing and assuming a friction coefficient of µ; = 1.0.

The vise shown consists of two members connected by two double-threaded screws with a mean radius of 0.25 in. and pitch of 0.08 in. The lower member is threaded at A and B (μs= 0.35), but the upper member is not threaded. It is desired to apply two equal and opposite forces of 120 lb on the blocks held between the jaws. (a) What screw should be adjusted first? (b) What is the maximum couple applied in tightening the second screw?

lock Page 7 of 8 Problem 6 4.0 kN 1.5 kN/m |A 1.0 m→1.0 m→* 2.0 m- For the beam shown above look at the location 1.1 meter to the right from the point A. Goal 1 (3 points) define formula to estimate shear force at the location of interest Goal 2 (2 points) calculate the value of shear force at the location of interest. Goal 3 (3 points) define formula for bending moment at the location of interest Goal 4 (2 points) calculate the value of bending moment for the location of interest.

A fuselage with a perfect circular cross-section with a diameter of 3.6 m and a skin thickness of 1.2 mm. Assume a pressure differential while flying at cruising altitude of 45 kPa. Calculate the circumferential stress induced by the pressure differential