Ball are dropped from the roop fo towar at fived interval if tiem . At the moment when9th ball reaches the groun the nth ball is (3//4) the heith of the tower Wgat the vale ofn ? G= 10 m//s^2.

Ball are dropped from the roop fo towar at fived interval if tiem . At

1.	Ball are dropped from the roop fo towar at fived interval if tiem . At the moment when9th ball reaches the groun the nth ball is (3//4) the heith of the tower Wgat the vale ofn ? G= 10 m//s^2.
Answer» SOLUTION :Let (t) be the time INTERVAL between TWO successive balls while falling . When `9th ` ball reaches the ground, the Ist ball is just to be dropped, os the time taken by the9th ball to reach the groun ` =(9 -1) t= 8 t` . `:. S= 1/2 xx g xx g xx (8t)^2 = 1/2 10 xx 64t^2 = 320 t^2 ` ...(i)` Time taken by nth ball to fall `= (n-1) t` DISTANCE travelled ` = s- 3 S/4` :. ` S/4 = 1/2 xx [(n-1)^2 t]^2 = 5 (n-a)t` or S= 20 (n-1)^2 t^2` ...(II) From (i) and (ii) ` 320 t^2 = 20 (n-1)^2t^2` On solving, ` n=5`.