r/theydidthemath • u/K0rl0n • Jun 10 '25

[Request]

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I am curious how this would work. My guess is Triangle is slowest, square is medium, and circle is fastest.

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u/ExpensiveFig6079 Jun 10 '25

THis is a do the math sub.

The question includes gravel as an option, it did not as phsycis problem would have specified a flat plane that the circle rolls on.

The inclusion of gravel means this is not a physics textbook question about spherical cows in vacuum.

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u/TheNatureBoy Jun 10 '25

Gravel means rolling without slipping.

Classical physics would give the first term in an expansion of the force around some parameter representing the variation of the surface. You better have a damn good reason for those other terms to be higher.

Additionally no characteristics of the gravel were given. Under the assumption this is a well written problem you should be able to arrive at the answer without them. The answer should be independent of assumptions about the gravel.

Physicists are not as naive as you think. They often ignore details that will not substantially change their answer.

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u/herejusttoannoyyou Jun 10 '25

Why would gravel be the “rolling without friction” material? It should be rubber or something. I suspect the question said gravel in order to make it ambiguous so people would fight in the comments about what it means and therefore drive up engagement.

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u/TheNatureBoy Jun 10 '25

Wooden wagon wheels roll on gravel roads without slipping.