If a steel ball is dropped it experiences free fall, what is it's velocity after 5 seconds? Disregard air resistance​

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

What is the fate of the electrons that interact with a specimen in an electron microscope?

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.