**1. The problem statement, all variables and given/known data**

**2. Relevant equations**

**3. The attempt at a solution**

I have dealt with the case when the wall is frictionless and the rolling ball collide with it but I am not sure how to proceed here. When the ball comes in contact with the wall, the friction due to wall acts in the vertically upward direction for a very short time. Hence,

$$\int fR\,dt=I(\omega_f-\omega_i)$$

and

$$\int f\,dt=mv_i$$

where ##f## is the friction due to wall and ##R## is the radius of ball. How do I relate ##v_i##, ##\omega_f## and ##\omega_i##? (where ##v_i## is the velocity acquired by ball in vertically upward direction.) :confused:

Also, which angle does the problem talks about? Is it the angle made by line joining the intersection of wall and floor with centre of ball and the ground? :confused:

Any help is appreciated. Thanks!

http://ift.tt/1fnty2Z