From what height should you drop a ball so that it hits the ground at 40 m/s? How long will it take to hit the ground? Please help, everyone is being useless

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 happens to an isotope during radioactive decay?

What is the quantity which is measured by the area occupied below the velocity- time graph?