Throwing a ball straight up

A ball is thrown straight up at $12\ \text{m/s}$. You will make the program find the time to the top and the greatest height on the Earth, and the time in the air on the Moon. Then it draws the height against the time on the Earth, with a dashed line at the greatest height.

The idea. On the way up the ball loses $g$ of speed every second, so it stops after $\dfrac{u}{g}$, at a height $\dfrac{u^2}{2g}$. The fall back takes as long as the rise.

Your tasks.

1. Work out t_top, the time to the top on the Earth, in seconds.
2. Work out h_max, the greatest height on the Earth, in metres.
3. Work out t_moon, the whole time in the air on the Moon, in seconds.