Which of the following energy sources is in no way derived from the sun? a) nuclear energy b)tidal energy c) wind energy d) petroleum

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.

If the new moon happens on january 15th, what shape will it be on february 6th?

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?