A ball is thrown directly upward into the air. The graph below shows the vertical position of the ball with respect to time. a. How much time does the ball take to reach its maximum height? b. How much time does the ball take to reach one-half its maximum height? c. Estimate the slope of ∆y/∆t at t = 0.05 s, t = 0.10 s, t = 0.15 s, and t = 0.20 s. On your paper, draw a coordinate system with velocity (v) on the y-axis and time (t) on the x-axis. Plot your velocity estimates against time. d. From your graph, determine what the acceler- ation on the ball is.