If a ring, disc, and a ball or equal mass and radius all were in a race down a ramp, which item would reach the bottom first? (Consider who would have the greatest translational KE)

A. Ring (hoop)
B. Disc (cylinder)
C. Ball (solid sphere)
D. None of the above it would be a tie due to having the same mass/radius

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.