Homework Help: Question about momentum depending if the collision is elastic or not?

nukeman · Oct 27, 2011

Question about momentum depending if the collision is elastic or not??

1. The problem statement, all variables and given/known data

Im writing up a lab, and there is something I can seem to get. Does the change in momentum depend on whether the collision is elastic or not? I know it does, but HOW?

For example collision of 2 carts, 1) collision with velcro on each cart, 2) attracting magnets on each cart 3) repeling magnets on each cart)

Is it reasonable to take as an approximation that the linear momentum of a system of collising macroscopic objects is conserved???

Thanks for any help!

2. Relevant equations

3. The attempt at a solution

LawrenceC · Oct 27, 2011

Re: Question about momentum depending if the collision is elastic or not??

When the collision is not an elastic one, there is a coefficient of restitution that comes into consideration. It takes on values between 0 and 1. It is one for an elastic collision. It is 0 for an inelastic collision.

In general:

Vb' - Va' = e * (Va - Vb)

where primes denote relative velocity after impact of two objects. e is the coefficient of restitution.

Redbelly98 · Oct 27, 2011

Re: Question about momentum depending if the collision is elastic or not??

Momentum does not change, as long as external forces are not present (or negligible). It does not matter whether the collision is elastic or not.

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Homework Help: Question about momentum depending if the collision is elastic or not?

nukeman

LawrenceC

Redbelly98