Free-Fall Acceleration
(a) With what speed must a ball be thrown vertically from ground level to rise to a maximum height of 50 $\mathrm{m} ?$ (b) How long will it be in the air? (c) Sketch graphs of $y, v,$ and $a$ versus $t$ for the ball. On the first two graphs, indicate the time at which 50 $\mathrm{m}$ is reached.