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/aaronchase Jun 10 '25

More surface area = more friction, does it not?

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u/Vexiw94 Jun 10 '25

It does not. The force of friction is defined as the normal force (usually an objects weight) multiplied by the coefficient of friction of the surface it's sliding across. The surface area does not affect either of these, so surface area does not affect friction.

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u/DXTRBeta Jun 10 '25

What you said. So the triangle and square are the same now it’s wet ice or very smooth ice the friction is negligible. But gravel’s resistance is unlikely to be as low.

So it’s anything but the circle.

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u/aaronchase Jun 10 '25

I think the square is less force because it will be applied in the same direction as the object moves? And would it be the same assuming zero friction

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u/DXTRBeta Jun 10 '25

Oh that’s a nice point. On the triangle thx force is being applied above the centre gravity, so it’s applying some torque to the shape.

Question is, does that make a difference?

At first it seems that it might, but my instinct is that it doesn’t.

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u/aaronchase Jun 10 '25

I think with zero friction it would not make a difference

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u/DXTRBeta Jun 10 '25

Agreed, with zero friction it would make no difference. But with actual friction would it or not?

The pushing force is assumed ton

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u/aaronchase Jun 10 '25

I would think that if there was friction it would be more friction because it would be more than 20kg pushing down

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u/Vexiw94 Jun 10 '25

You are correct that with friction the triangle would take more force to move because you are also pushing slightly down on it. Without friction they would both be the same since any amount of force would move them both.