Gordon, the night custodian, dusts off a classroom globe with a feather duster, causing the globe to acquire a charge of 8.0 *10^9 C. What is the magnitude and direction of the electric field at a point 0.40 m from the center of the charged globe?

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.