A ball is projected vertically up from ground. Boy A standing at the window of first floor of a nearby building observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is t_(1). Another boy B standing on the second floor notices that time interval between the ball passing him twice (during up motion and down motion) is t_(2). (a)Calculate the height difference (h) between the boy B and A. (b)Assume that the height of boy A from the point of projection of the ball is also equal to h and calculate the speed with which the ball was projected.

A ball is projected vertically up from ground. Boy A standing at the w

1.	A ball is projected vertically up from ground. Boy A standing at the window of first floor of a nearby building observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is t_(1). Another boy B standing on the second floor notices that time interval between the ball passing him twice (during up motion and down motion) is t_(2). (a)Calculate the height difference (h) between the boy B and A. (b)Assume that the height of boy A from the point of projection of the ball is also equal to h and calculate the speed with which the ball was projected.
Answer» Answer :(a) `H = (g(t_(1)^(2) - t_(2)^(2)))/(8)` (b) `u = (g)/(2) sqrt)2t_(1)^(2) - t_(2)^(2))`