What is the net work done to lift a 6 kg block a height of 5.3 meters and then lower it back to the ground where it started?

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.

What component of earth’s atmosphere exists entirely as a result of photosynthesis?

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius