Acube of mass m1=9.6 kgm1=9.6 kg is sitting on top of a second cube of the same size and mass m2=0.8 kgm2=0.8 kg while both are in free fall. ignoring any air resistance, what is the magnitude of the normal force with which the bottom cube is acting on the top cube?

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.