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All right, hello.
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In this question, we're given this setup, where we have two carts, one of mass 1 and one of mass 2.
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Mass 1, cart 1, is moving to the right with a speed of v1.
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And then it sticks to mass 2, and they go off together to the right.
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And we're asked various things about this situation, the first of which is, which of the following quantities is conserved during the collision? and we're given the options for linear momentum and kinetic energy.
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So is linear momentum conserved in this situation? so does our initial and our final linear momentum, are they equal to one another? well, in this case, yes.
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We don't have any external forces acting on the system.
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And that's what causes us not to be able to conserve linear momentum.
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So linear momentum is going to be conserved in this case, because there's no external forces acting on the system.
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We're asked if our kinetic energy is conserved in the system here.
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And so in the real world, because there's going to be some sound coming from this.
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So imagine you have the cart, and it's going to the right, and it hits, and there's going to be a little sound like that.
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It takes energy to create that sound.
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And that energy is coming from the fact that this cart was moving.
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So because it's the real world, it's not a perfectly elastic collision.
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And so our kinetic energy is not conserved.
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And i've explained why that's the case.
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So that's for part b.
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For part c, derive an expression for the final speed of the carts.
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So what is v final? well, we know our momentum is going to be conserved.
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So initially, we have only mass 1 moving, and it's moving with some speed v1.
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At the end, we have both mass 1 and mass 2 moving together with some speed v final.
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So v final is just going to be m1 times v1 over our total mass of our cart system.
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Part d then says, now the carts, which are stuck together, moved up a curved part of the track.
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So they're going along here, and they're going to go up this curved part of a track and then end up here at the top at some height h.
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And we're asked what quantities are conserved in this situation, linear momentum and or kinetic energy.
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So let's go ahead and think about that...