(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two air track gliders of a mass 300 g and 200 g are moving towards each other in opposite directions with speeds of 50 cm/s and 100cm/s respectively. Take the direction of the more massive glider as positive.

A.) determine the velocity of each glider after the collision if the collision is elastic.

2. Relevant equations

m1v1i +m2v2i = m1v1f + m2v2f

quoted by "collinsmark" - "You have enough information to solve it (given that this is a 1 dimensional problem -- things can get more complicated if the objects can freely move in more than 1 dimension)."

"You have the conservation of momentum equation that you listed above. But since you are assuming it is a perfectly elastic collision, you can also use conservation of kinetic energy (conservation of kinetic energy only applies if the collision is perfectly elastic). So you have 2 equations and 2 unknowns, which is solvable."

3. The attempt at a solution

I know collinsmark was right in what he is saying but i don't undrstand what formuals to use to get the seperate velocites.

Like this?

3(0.50) + 0.2(-1.00) = 0.3v1f

3(0.50) + 0.2(-1.00) = 0.2v2f

then solve for the seperate velocites in each case?

or just m1v1i = m1v1f

so the velocity doesnt change only in direction.

any help is greatly appreciated.

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# Homework Help: Dont understand this momentum problem

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