Elastic vs inelastic collisions formulas

  • Thread starter oneplusone
  • Start date
  • #1
127
2
When doing practice problems from my textbook, I often get confused with both of them.
MOre specifically there are usually formulas which pertain to only one of those types of collisions.

Ex: [itex] (v_1-v_2)_i = -(v_1-v_2)_f [/itex]

Does anyone know more of these types of formulas, or tricks to solve these equations?

Thanks.
 

Answers and Replies

  • #2
35,717
12,297
Does anyone know more of these types of formulas
Sure, your textbook.

or tricks to solve these equations?
- you can always use momentum conservation
- in elastic collisions, you can use energy conservation in addition
- in perfectly inelastic collisions, the objects stick together afterwards, so they have the same velocity
- in the center of mass system, all those collisions are easy to study

All equations are just a result of those ideas.
 
  • #3
1,506
18
Elastic collisions: KE is conserved, momentum is conserved
Inelastic collisions: KE is not conserved, momentum is conserved.
This is a reasonable starting point
 
  • #4
gmax137
Science Advisor
2,018
1,404
Also, don't be confused by the word "elastic." In common usage, "elastic" is like a rubber band or a balloon, that is, something "stretchy." BUT, when we say "elastic collision" in physics, examples are hard steel ball bearings (like you see in a Newton's Cradle toy) or billiard balls. Collisions of soft stretchy things (like soft rubber balls) are likely to be "inelastic." Confusing? I thought so when I learned this stuff the first time.
 
  • #5
elastic collision

if masses of two objects is same than in elastic collision there velocities get interchanged and if masses are not equal than you can use the formula which u have given for elastic collision.
 

Related Threads on Elastic vs inelastic collisions formulas

  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
10
Views
3K
Replies
11
Views
2K
  • Last Post
Replies
8
Views
886
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
9
Views
6K
Replies
8
Views
2K
Replies
3
Views
2K
Top