Suppose somehow a block of mass $m$ is moving on ground, and the coefficient of kinetic friction between the block and the block is $\mu_k$. If I drop a tennis ball(of same mass) on it from a height, say $h$ and it bounces back, coefficient of restitution being $e$ for the collision, I need to work out what effect would this have on its velocity, which was say at the time of collision equal to $v(t_0)=v$. The speed may or may not be changing due to everything else, but the change the collision would cause is what I want to find.
My view is that, at the time of collision, when the ball and the block are in contact, at that time ($t_0$), the normal reaction to the block will become $2mg$ instead of $mg$, which would change the kinetic friction at that time.
We say there is no change in momentum as impulse is due to opposite and equal magnitude forces. We say nothing about time. But here that time of contact is needed so that change in friction somehow changes the velocity.
Otherwise there is no extra change and so horizontal velocity shouldn't be affected by the collision. Does the velocity change due to collision?
Thanks in advance.[NO ROTATIONAL EFFECTS]