What is the vertical component of the velocity (in m/s) just before the ball hits the ground? (Indicate the direction with the sign of your answer.)

Question

A ball is thrown horizontally from the top of a 51.5-m building and lands 107.3 m from the base of the building. Ignore air resistance. (Assume the ball is thrown in the +x direction and upward to be in the +y direction.

With this information, how would I solve this?

Answer 1

v_y = gt

gt²/2 = h ⇒

t = √(2h/g)

v_y = gt = g √(2h/g)

You know g and h. Plug in the numbers and get v_y in m/s. Since down is negative, put a minus sign in front of the answer.