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I did not watch this video but did read about this math. Visualize the larger circle unwrapped into a flat line, and the smaller circle sliding along the length of the line so its bottom point is fixed to the line. You’ll see the small circle never rotates. Now slide the small circle with a point fixed onto the large circle in the same way, and you’ll see the small circle makes one complete rotation. That rotation happens in addition to the rotations you get from dividing the larger circumference by the smaller circumference, so the answer is 4 in this case
That’s what you’d think, but there’s an extra rotation involved in the act of the small circle moving around the larger circle rather than along a straight line, so it’s (6π/2π) + 1
The center travels 2π per rotation but need to travel 8π because the path of the center of the small circle is a circle 4r the radius of the large circle plus the radius of the small circle.
It would be three if the center of the small circle traveled along the edge of the larger circle but it’s edge to edge.
I did not watch this video but did read about this math. Visualize the larger circle unwrapped into a flat line, and the smaller circle sliding along the length of the line so its bottom point is fixed to the line. You’ll see the small circle never rotates. Now slide the small circle with a point fixed onto the large circle in the same way, and you’ll see the small circle makes one complete rotation. That rotation happens in addition to the rotations you get from dividing the larger circumference by the smaller circumference, so the answer is 4 in this case
Satellite operators have to use this equation for orbits.
Wouldn’t it be 3 = 6π/2π ?
if the path had been straight yeah, but the path itself rotates 360 degrees, which gives us an extra rotation
This is the comment that finally enlightened me
Thank you
This finally made it click. Thanks
Now that is mind-bending trickery! Having a degree in applied matha millennia ago did not help…
That’s what you’d think, but there’s an extra rotation involved in the act of the small circle moving around the larger circle rather than along a straight line, so it’s (6π/2π) + 1
I just watched the video, that’s really interesting. Thanks for the explanation
Watch the video, it’s explained.
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The center travels 2π per rotation but need to travel 8π because the path of the center of the small circle is a circle 4r the radius of the large circle plus the radius of the small circle. It would be three if the center of the small circle traveled along the edge of the larger circle but it’s edge to edge.
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