Colliding particles with equal masses with given elasticity

In summary: M-E*M)}{M+m}v_{2f}=\frac{v(m-Em)}{M+m}In summary, we have two particles with equal masses m colliding with elasticity E = 0.650. We are trying to find the final velocities of the particles, with particle 1 having an initial velocity v and particle 2 being initially at rest. Using the equations mv_{1i}+mv_{2i}=mv and v_{2f}-v_{1f}=Ev, we solve for v_{1f} and v_{2f} to get the final velocities in terms of v. However, this approach may not work if
  • #1
Superfluous
11
1
If the two particles with equal masses m collide with elasticity E = 0.650 , what are the final velocities of the particles? Assume that particle 1 has initial velocity v and particle 2 is initially at rest.

Give the velocity [tex]v_{1}[/tex] of particle 1 and the velocity [tex]v_{2}[/tex] of particle 2. Express the velocities in terms of v.

What I know...

[tex]mv_{1i}+mv_{2i}=mv[/tex]

[tex]v_{2f}-v_{1f}=Ev}[/tex]

I tried to use these two equations to solve for it, but it doesn't work out. My problem is that I know I'm supposed to use these equations to solve this, but I can't figure out exactly what to do with them. Solving the first equation for v and then substituting it into the second equation doesn't get me anywhere.
 
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  • #2
By elasticity do you mean coefficient of restitution? If so it is

[tex] \epsilon = \frac{|v_{2f} - v_{1f}|}{|v_{2i}-v_{1i}|}[/tex]

you might have the wrong formula.

Also, another problem I see is that you are assuming an inelastic collision with your momentum equation. This is not necessarily true. Inelasticity works when your coefficient of restitution is zero, or approximately low.
 
  • #3
Superfluous said:
What I know...

[tex]mv_{1i}+mv_{2i}=mv[/tex]

I guess, the correct formula is, [tex]mv_{1f}+mv_{2f}=mv[/tex].
Now solve, you should get.
 

Related to Colliding particles with equal masses with given elasticity

1. How do you calculate the final velocities after two particles collide?

The final velocities of two colliding particles can be calculated using the conservation of momentum and conservation of kinetic energy equations. The equations are as follows:

Momentum conservation: m1v1i + m2v2i = m1v1f + m2v2f

Kinetic energy conservation: 1/2m1v1i2 + 1/2m2v2i2 = 1/2m1v1f2 + 1/2m2v2f2

2. What is the formula for calculating the coefficient of restitution?

The coefficient of restitution, denoted by e, is a measure of the elasticity of a collision between two particles. It can be calculated using the following formula:

Coefficient of restitution: e = (v2f - v1f) / (v1i - v2i)

Where v1i and v2i are the initial velocities of the particles and v1f and v2f are the final velocities after the collision.

3. What happens to the kinetic energy of colliding particles with equal masses and high elasticity?

When two particles with equal masses collide and have high elasticity, the kinetic energy of the system is conserved. This means that the total kinetic energy before the collision is equal to the total kinetic energy after the collision. This is due to the fact that the particles bounce off each other with minimal energy loss, resulting in a highly elastic collision.

4. How does the elasticity of a collision affect the final velocities of particles?

The elasticity of a collision directly affects the final velocities of particles. In a perfectly elastic collision, the final velocities of the particles will be equal to their initial velocities, but in opposite directions. As the elasticity decreases, the final velocities will be lower and may not be equal to the initial velocities.

5. Can two particles with equal masses and low elasticity stick together after a collision?

Yes, it is possible for two particles with equal masses and low elasticity to stick together after a collision. This type of collision is known as a perfectly inelastic collision. In this case, the final velocities of the particles will be zero as they stick together and move as one combined mass.

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