A ball of mass m collides horizontally with a stationary wedge on a rough horizontal surface, in the two orientations as shown. neglect friction between the ball and the wedge. The students comment on the system of ball and wedge in these situations.
Saurav: Movements of the system in x-direction will change by significant amount in both the cases.
Rahul: There are no impulsive external forces in x-direction in both cases, hence the total momentum of the system in x-direction can be treated as conserved in both cases.