Solving Three Ball Collision: Elastic Collision with M and m Masses

In summary, the conversation discusses an elastic collision between a ball of mass M and two balls of mass m. The initial conditions include M moving with velocity v while the two balls are stationary. The question is to find the velocity of M after the collision. The equations for this problem involve four unknowns and three equations, which leads to difficulty in solving.
  • #1
momo1111
10
0

Homework Statement


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Ball of mass M collide two balls of mass m , elastic collision .
initially, M has velocity v , and two balls are stationary.
after the collision the two masses move ,like in figure , v_a , v_b /
What is the velocity V ,of mass M after the collision ?


Homework Equations

The Attempt at a Solution


1231.png

try to manipulate the equations , with no success.
help
 

Attachments

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  • #2
Your notation is a bit confusing, but I think I get it.

Consider that you have four scalar unknowns (vx, vy, v1, and v2) but only three equations.
 
  • #3
fix notation
upload_2015-7-11_20-27-5.png
 
  • #4
Dr. Courtney said:
Consider that you have four scalar unknowns (vx, vy, v1, and v2) but only three equations.
The way I read it, vA, vB are given, so it's 3 equations and 2 unknowns. Still not good. Could choose to ignore the elasticity condition.

momo, are you sure you have quoted the question exactly?
I assume your last equation in post #3 should read v'2=v'x2+v'y2.
 

1. How do you solve for three ball collisions with elastic collisions and masses M and m?

To solve for three ball collisions with elastic collisions and masses M and m, you can use the equations of conservation of momentum and conservation of kinetic energy. These equations allow you to calculate the final velocities of the balls after the collision.

2. What is the difference between elastic and inelastic collisions?

In an elastic collision, both momentum and kinetic energy are conserved, meaning that the total momentum and total kinetic energy of the system before and after the collision remain constant. In an inelastic collision, only momentum is conserved, but kinetic energy is not. Some energy is lost to heat or sound.

3. Can you explain the concept of coefficient of restitution in three ball collisions?

The coefficient of restitution is a measure of the elasticity of a collision. It is defined as the ratio of the relative velocity of separation to the relative velocity of approach. In three ball collisions, the coefficient of restitution can help determine the final velocities of the balls after the collision.

4. Are there any assumptions made when solving for three ball collisions?

Yes, there are a few assumptions that are made when solving for three ball collisions. These include assuming that the balls are perfectly spherical, that there is no external force acting on the system, and that the collision is happening in a vacuum.

5. Can you provide an example of a real-life application of solving for three ball collisions?

One real-life application of solving for three ball collisions is in the game of billiards. When the cue ball hits two other balls, the collision between the three balls can be modeled and predicted using the equations of conservation of momentum and kinetic energy. This can help players strategize and make accurate shots.

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