The following formulas are commonly used by engineers to predict

The following formulas are commonly used by engineers to predict the lift and drag of an airfoil:

where L and D are the lift and drag forces, V is the airspeed, S is the wing span, ρ is the air density, and C_L and C_D are the lift and drag coefficients.

Both C_L and C_D depend on α, the angle of attack, the angle between the relative air velocity and the airfoil’s chord line.

Wind tunnel experiments for a particular airfoil have resulted in the following formulas.

where α is in degrees.

Plot the lift and drag of this airfoil versus V for 0 ≤ V ≤ 150 mi/hr (you must convert V to ft /sec; there is 5280 ft/mi). Use the values ρ = 0.002378 slug/ft³ (air density at sea level), α = 10°, and S = 36 ft. The resulting values of L and D will be in pounds.