Wave propagation with water moving

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Homework Help Overview

The problem involves wave propagation in a moving medium, specifically water, with two fish positioned equidistant from a fishing pole creating waves. The scenario raises questions about which fish would experience the wave first, considering the movement of the water and the characteristics of the wave.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the influence of water velocity on wave propagation and whether the fish would feel the waves simultaneously. There are considerations about the reference frame of the water and the implications of the water's movement on the timing of wave impact on the fish.

Discussion Status

The discussion is ongoing, with various interpretations being explored. Some participants suggest focusing on the most likely scenarios, while others express uncertainty about the assumptions made in the problem statement. There is no explicit consensus, and the potential for the problem to be a trick question is noted.

Contextual Notes

Participants mention constraints such as the water not moving faster than the velocity of the waves and the assumption that the fish remain relatively stationary, which may influence the outcome of the problem.

fish.frog
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Homework Statement


Suppose a person is fishing and is bobbing the fishing pole in constant intervals, there are 2 fish in the water located in the same distance L from the fishing pole (the source of the wave).
Suppose also the water is moving from A to B. Which fish will feel the wave first?
Snapshot.jpg


Homework Equations

& The attempt at a solution[/B]
Firstly I hope the problem statement is clear as it was translated. Do you believe the answer is uniquely determined? To me it seems to depend on the velocity of the water and the the period Of the wave.
If only one wave was created and the water was moving with the fish with it, both fish would feel the wave in the same time.
But if the water was moving fast, with the appropriate period of the wave, you might create a situation where fish A would get hit by the second wave before the first wave. (Perhaps by hitting the fish with the hook of the fishing pole)

The answer given is both fish would feel the wave in the same time by considering the reference frame of the water. But does this answer really considers the case I gave?
 
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fish.frog said:
But if the water was moving fast, with the appropriate period of the wave, you might create a situation where fish A would get hit by the second wave before the first wave.
You can assume that the water is not moving faster than the velocity of the waves.

Also, I think the fish stay in place.
 
In addition to what mfb said, don't think of every exception to the answer. Think about the most likely situation (which would not include the water moving faster than the velocity of the waves). I used to think about these kind of problems too hard, and my science teacher got really mad.
 
mfb said:
You can assume that the water is not moving faster than the velocity of the waves.

Also, I think the fish stay in place.
mfb, I agree with your first advice above, but I'm not so sure about the second. Anybody who goes angling in streams will be aware that fish do tend to swim against the current so as to stay more-or-less in one spot for a while, but that does not necessarily apply to the author of the puzzle. I have a nasty feeling it may be intended as a trick question.
 

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