The discussion revolves around the concept of impulse and momentum in the context of a tennis player throwing a ball against a wall. Participants are exploring which scenario—throwing, bouncing, or catching the ball—results in the greatest change in momentum.
There is a productive exchange of ideas, with participants confirming each other's reasoning regarding the bounce having the greatest change in momentum. Some participants are also questioning the initial conditions for the throw scenario, indicating a deeper exploration of the concepts involved.
Assumptions about kinetic energy loss are mentioned, but participants note that this does not affect their reasoning regarding momentum changes. There is an implicit understanding that the discussion is framed within the constraints of a homework assignment.
IssacNewton said:yes you are right. bounce has the greatest change in momentum. let's say that velocity before the impact is [tex]\vec{v}[/tex] , then velocity after the bounce would be
[tex]-\vec{v}[/tex]. so initial momentum is [tex]m\vec{v}[/tex] and final momentum is
[tex]-m\vec{v}[/tex]. so the change in momentum would be [tex]-m\vec{v}-m\vec{v}[/tex] which is [tex]-2m\vec{v}[/tex]. but when the ball is caught, final momentum is zero, so the change in momentum is [tex]0-m\vec{v}[/tex] which is [tex]-m\vec{v}[/tex]
same argument can be made for the case when the the ball is thrown.
Edit: I am assuming above that the kinetic energy is not lost. Even if the kinetic energy is lost, the reasoning is not affected.