Collision of Balls - Coefficient of Restitution

  • Thread starter Thread starter prateek_34gem
  • Start date Start date
  • Tags Tags
    Balls
Click For Summary

Homework Help Overview

The problem involves a collision scenario with three balls, where two balls are initially at rest and a third ball collides with them. The focus is on determining the coefficient of restitution based on the conditions of the collision.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of conservation of momentum and the coefficient of restitution equations. There is a question about whether to treat the two resting balls as one entity or consider them separately in the analysis.

Discussion Status

Some participants have attempted calculations for the coefficient of restitution, with one stating a result of e=1/2, while expressing uncertainty about the correctness of this answer compared to a suggested answer of 2/3 from a book. The discussion reflects differing interpretations of the problem setup.

Contextual Notes

There is a mention of potential confusion regarding the treatment of the two resting balls and the implications of their motion on the calculations. The problem context suggests that assumptions about the system's behavior may need clarification.

prateek_34gem
Messages
15
Reaction score
0

Homework Statement



Two equal balls are in contact on a table and are in equillibrium. A third ball collides with them simultaneously, symetrically and remains at rest after the impact. The coefficient of restitution is :

A)2/3
B)3/2
C)1/3
D)1/2

Homework Equations





The Attempt at a Solution


i have tried by combining the masses and velocities of the two balls at rest then found e. like the collision of two bodies ( considering two bodies as one ) .
 
Physics news on Phys.org
You have 2 equations that you would satisfy don't you?

Conservation of momentum which gives you the relationship between the initial velocity of the first ball and the final velocity of the second 2.

Then you have the equation for the coefficient of restitution that relates the before and after velocities of the 2 bodies. (This is simplified by the fact that before the collision only 1 was in motion. And after the collision the first becomes stationary.)
 
but there are two balls lying at rest do i have to consider the motion of only one of thm or take them whole as one ?
 
Last edited:
i have got e=1/2
but thts wrong ans . Correct ans . is 2/3
is ans given in book wrong or i am wrong ??
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
988
  • · Replies 2 ·
Replies
2
Views
3K
Replies
17
Views
8K
Replies
34
Views
3K
Replies
20
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 10 ·
Replies
10
Views
5K
Replies
6
Views
3K