Calculating Momentum and Collisions in Repetitive Collision Problems

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The discussion centers on calculating various aspects of a repetitive collision problem involving a spherical mass dropping from a height. Key points include determining the total distance covered, the number of collisions, the total time taken after n collisions, and the change in momentum after these collisions. Participants emphasize the importance of understanding the coefficient of restitution and the height the ball rebounds to after each collision. It is suggested that the user should first calculate the rebound height after the initial collision to identify a pattern, which can simplify subsequent calculations. Overall, the conversation highlights the need for foundational understanding before tackling complex repetitive collision problems.
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I have a doubt in repetitive collision problem. A spherical mass m is striking the ground from a height h. The coefficient of restitution b.w ground and the spherical ball is e. If n collisions take place before coming to rest.
1)What is the total distance covered by the spherical ball before coming to rest. (There is no friction between ground and the ball. )
2) Total number of collisions
3)the total time taken after n collisions.
4)the total change in momentum after n collsions.
 
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That's a standard textbook question (though, the statement about 'n' collisions is only an approximation). So what exactly is your doubt regarding this? We can not help you unless you first show some effort. And please read the posting Guidelines.
 
Zarbon said:
I have a doubt in repetitive collision problem. A spherical mass m is striking the ground from a height h. The coefficient of restitution b.w ground and the spherical ball is e. If n collisions take place before coming to rest.
1)What is the total distance covered by the spherical ball before coming to rest. (There is no friction between ground and the ball. )
2) Total number of collisions
3)the total time taken after n collisions.
4)the total change in momentum after n collsions.

First, you should find out how much of the original height the ball jumps back to from which it was dropped.

(Hi Mentor, Pl shift this to the HW forum.)
 
First calculate how much height it will rise after it's first collision (I hope you can do this), then find out for the second, then third.
by now, you may have started noticing an interesting pattern in the heights (I won't spoil the fun, find out yourself)
 
He has to calculate just once to what fraction of H is the ball jumping back to. If that fraction is a constant, he does not have to calculate for n times.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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