Well, if you’re rotating these coins on a treadmill all bets are off.Ok, but can the coin take off?
Ok, but can the coin take off?
I’ve watched YT videos and still can’t grasp it.Next problem: explain how planetary gears work.
The answer would be 3 if it was on a flat surface. It’s 4 because it’s not a flat surface.Problem shows radius of 3 and 1 inch. Circumference of 3 divided by 1 = 3. Put it on a flat surface. The radius of a 3 inch circle is .478 and radius of a 1 inch circle is .159.
I don't followNo. That’s the gotcha of the problem and is not correct.
This gave me a headache.
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This is the explanation I found which then took me down the sidereal orbital period rabbit hole.Think about it from the perspective of the center of the small coin.
Yes, its circumference is 1. If you roll it on a flat surface for three inches, the center travels 3 inches, in a straight line
But think about how far the center is traveling when it goes around the big circle. The center is now traveling in a circle, and that circle's circumference has changed.
Instead of moving in just a straight line, equal to the circumference of itself 2*pi*r = 1, the center is now moving in a circle with a circumference of 2*pi*(R+1) = whatever (more than 1). That is where the extra movement is coming from.