6. A 0.045 kg bullet is fired at 340 m/s at a 3.5 kg wooden block that is hanging from a 3 m long string. If the bullet passes through the block and emerges out the other side traveling at 50 m/s, what angle does
the string make with the vertical when the block gets to its highest position?

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.