Question

if a ball with an original velocity of 0 is dropped from a tall structure and takes 7 Seconds to hit the ground what velocity does the ball have when it reaches the ground

Answer 1

`a_y=\frac{v_y-v_(0y)}t\implies-9.81\,(\mathrm m)/(\mathrm s^2)=(v_y-0)/(7\,\mathrm s)\implies v_y=-68.7\,(\mathrm m)/(\mathrm s)`