2D Elastic Collision equations

Click For Summary
The discussion focuses on the equations governing 2D elastic collisions, emphasizing the principles of conservation of momentum and energy. Key equations are provided for momentum conservation in both the x and y directions, as well as the energy conservation equation, noting that for elastic collisions, kinetic energy loss (Q) is zero. The importance of understanding these principles is highlighted for solving collision problems effectively. Additionally, the user seeks resources for both 2D and 3D collision equations to aid in developing a collision simulation program. The mention of using Newton diagrams for geometric solutions to 2D collisions offers a practical approach to the topic.
vip4
Messages
4
Reaction score
0
Does anyone know the equations for 2D elastic collisions.
 
Physics news on Phys.org
Don't just learn the equations. Learn the principles behind those equations. You will always have conservation of momentum in any collision. For elastic collisions energy is also conserved. This will give you enough info the solve any collision problem, in principle anyway.
 
Conservation of momentum:

m_1 v_1 \cos \theta_1 + m_2 v_2 \cos \theta_2 = m_1 v_1^\prime \cos \theta_1^\prime + m_2 v_2^\prime \cos \theta_2^\prime

m_1 v_1 \sin \theta_1 + m_2 v_2 \sin \theta_2 = m_1 v_1^\prime \sin \theta_1^\prime + m_2 v_2^\prime \sin \theta_2^\prime

Conservation of energy:

\frac{1}{2} m_1 v_1^2 + \frac{1}{2} m_2 v_2^2 = \frac{1}{2} m_1 {v_1^\prime}^2 + \frac{1}{2} m_2 {v_2^\prime}^2 + Q

where Q is the amount of kinetic energy lost in the collision (to "heat" or whatever). For an elastic collision, Q = 0.
 
Thanks for the reply galileo and jtbell. I have done a little reading on conservation of momentum and energy. I also search the internet for the equations and the theories involved in collisions. However i could only find 1D equations.

I would appreciate it if you could point me to any information that could help me to better understand it. I would also like any information on 3D collisions as well. The reason I'm trying to get this information is to write a computer program that simulates collisions.
 
I remember a neat way to solve 2D collision problems geometrically. Google for Newton diagrams.
 
For simple comparison, I think the same thought process can be followed as a block slides down a hill, - for block down hill, simple starting PE of mgh to final max KE 0.5mv^2 - comparing PE1 to max KE2 would result in finding the work friction did through the process. efficiency is just 100*KE2/PE1. If a mousetrap car travels along a flat surface, a starting PE of 0.5 k th^2 can be measured and maximum velocity of the car can also be measured. If energy efficiency is defined by...

Similar threads

Replies
5
Views
4K
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
285
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 41 ·
2
Replies
41
Views
2K
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K