A large tank containing a liquid is at rest on ground and base of tank is horizontal. Two balls A and B are thrown simultaneously with same speed u at same angle θ with the vertical wall of tank.

Ball A is thrown from a point just inside of liquid while ball B is thrown from bottom of tank. If density of liquid is ρ L , density of ball A is ρ A = and density of ball B is ρ B = 2 ρ L . Assuming all resistances in motions of balls to be negligible, and g = 10 m/s 2 .

(i) If h = 20 m then the maximum value of u so that ball do not collide with each other for any value of θ–