What is the mass of an asteroid with a speed of 200 m/s and a momentum of 2,000 kg m/s? A. 2200 kg
B. 10 kg
C. 400,000 kg
D. 1,800 kg

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.