00:01
In this problem, we are given two balls with different masses and given velocities that are in motion, and they collide with each other as in the figure.
00:13
They then move off with final velocities, va and vb, which we wish to calculate.
00:19
We are also given the coefficient of restitution for the system.
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The first thing we will do here is apply the conservation of momentum, the conservation of linear momentum, and will the velocity of ball's a and b before and after the impact can be seen in the diagram.
00:40
So applying the conservation of momentum and taking the right direction as positive, we have that the momentum of ball a, m -a, v -a, initially, so that's subscript 1, plus the initial momentum of ball b, m -b -b -1, must equal to the momentum after the collision, which is m .a.
01:07
V .a.
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2 plus m .b.
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V .b.
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2.
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This is after the collision.
01:17
So the mass of ball a, we know, is 3 kg.
01:20
And its velocity is 8 meters per second to the right.
01:25
The momentum for ball 2 is its mass, or ball b rather, mass 2 kg times its velocity, which is 4 meters per second, but it's to the left...