Conservation of energy in elastic collision

AI Thread Summary
In elastic collisions, both energy and momentum are conserved, which leads to changes in the velocities of the colliding objects. The discussion centers on a specific problem where block 2's energy appears to increase after the collision, despite its velocity changing from negative to positive. The confusion arises from the understanding that kinetic energy depends on the square of velocity, suggesting that a change in direction should not affect energy. The computer's answer indicates an increase in energy, prompting questions about the expected behavior of the smaller object in the collision. Overall, the conversation emphasizes the complexities of energy conservation in elastic collisions.
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Homework Statement



http://www.screencast.com/users/ntrinh3/folders/Jing/media/a4165a56-de0d-4a4a-a01e-49242fd505c4
Need help with question 13

Homework Equations



Conservation of energy and momentum occurs in elastic collision

The Attempt at a Solution



Why would the block 2 have an increase in energy? The velocity of block 2 will now be positive instead of negative but velocity is squared anyway.
The computer's answer was A. Increase, but shouldn't it remain the same?
 
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Imagine the situation here. A much much heavier object slams into an object with comparable (actually, the same!) speeds. What do you expect the smaller object to do?
 

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