Elastic Collisions (Oblique Impact)

In summary, the conversation discusses the understanding of reversed horizontal velocities after a collision and the importance of knowing the direction of these velocities to solve the problem correctly. The concept of the coefficient of restitution is also mentioned. The conversation ends with the realization that the Newton's Law of Restitution was being applied incorrectly.
  • #1
FeDeX_LaTeX
Gold Member
437
13
http://desmond.imageshack.us/Himg843/scaled.php?server=843&filename=23518417.jpg&res=medium

The crucial thing I'm not understanding here is how they know that after the collision (shown at the bottom of the picture), the horizontal velocities of each particle are reversed. Surely we don't know that, though? However, the direction after is important because I'm getting a different answer if I just try to get v or w by itself. When I draw my diagram for what happens post-impact, I'm not giving v and w a direction, I'm just labelling them as horizontal components. However, to solve this question I think you need to know which direction they're in.

Any help?

EDIT: Sorry about image quality. Co-eff of restitution is 3/4.
 
Last edited by a moderator:
Mathematics news on Phys.org
  • #2
Eh, never mind, sorry. I was being an idiot, of course it shouldn't matter. I was doing Newton's Law of Restitution the wrong way round...
 

1. What is an elastic collision?

An elastic collision is a type of collision between two objects in which both kinetic energy and momentum are conserved. This means that the total energy and total momentum before and after the collision remain the same.

2. What is the difference between an elastic and inelastic collision?

In an elastic collision, both kinetic energy and momentum are conserved, while in an inelastic collision, only momentum is conserved. In an inelastic collision, some of the kinetic energy is converted into other forms of energy, such as heat or sound.

3. How is the angle of impact important in an elastic collision?

The angle of impact is important in an elastic collision because it determines the direction and magnitude of the velocities of the objects after the collision. In an oblique impact, the angle of impact will affect the final velocities of both objects in different ways.

4. What factors can affect the outcome of an elastic collision?

The outcome of an elastic collision can be affected by factors such as the masses and velocities of the objects, the angle of impact, and any external forces acting on the objects. The elasticity and shape of the objects can also play a role.

5. Can an elastic collision ever result in perfect conservation of energy?

Yes, in a perfectly elastic collision, the objects will retain all of their initial kinetic energy and no energy will be lost to other forms. However, in real-world situations, some energy is always lost due to factors such as friction and air resistance.

Similar threads

Replies
30
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
864
  • Introductory Physics Homework Help
Replies
15
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
878
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
16
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
3K
Back
Top