Question

A rock is thrown vertically upward from ground level. After 1.5 s it passes the top of a tall tower and 1.0 s later it reaches its maximum height. What is the height of the tower (g = 10 m/s2)?

Answer 1

The maximum height of the rock is

$$H=gT^2/2=11.25m.$$

0.5 second is required to get from to of the building to the maximum height of the rock:

$$h=H-gt^2/2=10m.$$