Understanding Elastic Collisions: Solving a Head-On Collision Problem

AI Thread Summary
In an elastic collision problem, a 6 gram ball moving north at 3 m/s collides with an identical ball moving south at 2 m/s, resulting in the first ball moving south at 1 m/s. The key issue raised is the apparent contradiction in energy conservation, as the expected velocity of the second ball is questioned. The solution guide suggests the second ball moves off at 2.0 m/s, which leads to confusion regarding energy conservation principles. Participants express skepticism about the problem's wording and its implications for physical laws. Clarification is sought on whether the problem is misworded or if it presents an unrealistic scenario in physics.
cybernerd
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Homework Statement



A 6 gram ball moving north at a rate of 3 m/s collides head on with an identical ball moving south at 2.0 m/s. The collision is elastic and the first ball moves south at 1 m/s. What is the velocity of the second ball?

Homework Equations



Law of conservation of momentum.
p=mv

The Attempt at a Solution



The question makes no sense to me. According to my solution guide, the other ball moves off at 2.0 m/s. But of the collision is elastic, then no energy should be wasted. So...2.0m/s worth of energy from the first ball is sucked into an abyss? Can anyone shed light on this?
 
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Yeah I don't know about this one. Energy's definitely not conserved using the given data. Chalk it up to a miswording?
 
I hope so, or we're getting into magic rather than physics...thanks for confirming this...
 
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