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Aug30-07, 09:06 PM
P: 53
1. The problem statement, all variables and given/known data

Imagine that I throw a ball toward the floor. It hits the floor and rebounds upward. What type of fundamental interaction between the atoms of the floor and the ball causes the ball to rebound upward?

a. Strong nuclear
b. Electromagnetic
c. Weak nuclear
d. Gravitational
e. Some combination of the above
f. Some other kind of interaction

2. Relevant equations


3. The attempt at a solution

If the question is indeed only concerned with the rebound upward and not its descent, then I could first eliminate (d) gravitational interaction as a possible answer (I am not sure about this). Since this is a macroscopic interaction, I also eliminate (a) and (c). Because I am only left with (b) out of the above interactions, I can eliminate (e).

If my reasoning is correct so far, the answer is either (b) or (f). It seems that the rebound upward would have something to do with a type of contact interaction--friction, compression, or tension. Is (d) still a possible answer, since if gravity were stronger, the ball could not rebound? If it is the case that all contact interactions are really just complicated electromagnetic interactions, should I confidently place (b) as my final answer?

I cannot be confident about choosing any answer. Any help would be greatly appreciated.

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