An RC circuit has a 55.0 mu F capacitor connected to a 780 ohm resistor. a). When the capacitor is charged, how long does it take for the capacitor to reach 80% of full capacity

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.