Coins

Originally posted by The Plumber
Well, if you go out to the 23rd dimension, I can see that, but if you limit it to 2, the answer is gonna' be pretty much three and a third....

He clearly said "dimentions", which as everyone knows is what the demented call dementia. So technically, he's insane!
😉

Originally posted by PBE6
He clearly said "dimentions", which as everyone knows is what the demented call dementia. So technically, he's insane!
😉

My apologies, you're quite right. If we carry it out to the third dimention, then it must be three....🙄

Originally posted by XanthosNZ
Let the radius of the coins be r.
Now look at what distance the center of the moving coin travels. It's 4*pi*r. That's twice the circumfrence of the coin so it makes two rotations.

Rotations and revolutions are not the same thing if I remember what I learned about the solar system correctly. Rotations are like the way the Earth rotates about it's axis, while revolutions are like the way the Earth goes around the sun. No?

I guess I don't understand what a "revolution" and a "rotation" are. Can someone clarify?

Originally posted by AThousandYoung
Rotations and revolutions are not the same thing if I remember what I learned about the solar system correctly. Rotations are like the way the Earth rotates about it's axis, while revolutions are like the way the Earth goes around the sun. No?

I guess I don't understand what a "revolution" and a "rotation" are. Can someone clarify?

I believe you are right.
Revolution is the repetitive evolution on a traject. In the case of gravity, it is an elliptic traject around another mass positioned in one of the focal points.
Rotation requires an axis, and the motion is circular. Like a planet rotating around its own center of gravity.

Originally posted by Mephisto2
I believe you are right.
Revolution is the repetitive evolution on a traject. In the case of gravity, it is an elliptic traject around another mass positioned in one of the focal points.
Rotation requires an axis, and the motion is circular. Like a planet rotating around its own center of gravity.

So...if the coin goes around the entire circumference of the other coin, it ends up back where it started. This describes one revolution. The coin rotated twice however because halfway through the revolution the coin is oriented the same way it was when it started - it's rotated once.

So, one revolution, two rotations.