## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

Since the ball passes Chad with a speed of 10 m/s on the way down, the ball had a speed of 10 m/s when it passed Chad on the way up. We can find the initial speed of the ball as: $v_0^2 = v^2-2ay$ $v_0 = \sqrt{v^2-2ay}$ $v_0 = \sqrt{(10~m/s)^2-(2)(-9.8~m/s^2)(5.0~m)}$ $v_0=14~m/s$ Nicole threw the ball with a speed of 14 m/s.