A ball is projected on a very long floor. There may be two conditions `(i)` floor is smooth `&
Channel: Doubtnut
Date: 2020-01-26

A ball is projected on a very long floor. There may be two conditions `(i)` floor is smooth `& (ii)` the collision is elastic If both the considered then the path of ball is as follows. Now if collision is inelastic and surface is rough then the path is as follows. Successive range is decreasing . Roughness of surface decreases the horizontal component of ball during collision and inelastic nature of collision decreases the vertical component of velocity of ball. In first case both components remain unchanged in magnitude and in second case both the components of the velocity will change. Let us consider a third case here surface is rough but the collision of ball with floor is elastic. A ball is projected withe speed `u` at an angle `30^(@)` with horizontal and it is known that after collision with the floor its speed becomes `(u)/(sqrt(3))` . Then answer the following questions. The angle made by the resultant velocity vector of the ball with horizontal after first collision with floor is `:`