can you help me solve this word problem i cannot figure out?

Question

Jacob drops a ball from the roof of his apartment building. The ball’s initial height is 12 meters. Use to find an equation for the height of the ball after t seconds. Write this in your notebook. Find the height of the ball after .5 seconds. Round your answer to the nearest tenth of a meter.

Answer 1

Let H be the height from where the ball is dropped ( taking ground as reference )

 

h= height of the ball after t seconds 

 

Then H - h = 1/2gt² is the equation to be used

 

where g=9.8 m/s²

 

Given H = 12 m t = 0.5 sec

 

12 -h = 1/2 (9.8) (0.5 ) (0.5)

 

from this h may be calculated