Two boys are standing at the ends A and B of the ground where distance AB = a . The body at b startsand direction perpendicular ABwith velocity . the at A starts standing and catches the other boy in time T

Let the boy A catch boy B in time T Then, AB = a BO = vT [because velocity of B is v, then dist covered is vT ] Let velocity of A be v¹ By Pythagoras thm, (AO)² = (AB)² + (OB)² (v¹T)² = a² + (vT)² T = a.√([v¹]² - v²)