A stone drop from the top the tree covers 6m height in last 0.2 second of fall find the height of the tree

Let h(t) be the position of the ball after t seconds. When the ball hits the ground, h(t)=0. Let c be the height of the tower. Then:

0=-4.9t²+vt+c

Here, we have no initial velocity v. And we have two equations:

c=4.9t² and

c-6=4.9(t-0.2)²

So:

4.9t²=4.9(t-0.2)²+6

4.9t²=4.9t²-1.96t+0.196+6

1.96t=6.196

t=3.16122 secs

4.9 x (3.16122)²= about 49m