Thread: Center of the Circle Path

If a circle of radius 2 is made to roll along the x-axis, what is an equation for the path of the center of the circle?

Does it seem reasonable to you that the radius of a circle remains constant?

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A good question


Move the red point to see the "shape" it makes.









You really should have been able to do this in your head.

I'm sorry but your answers do not make sense.

Can you help me?

Originally Posted by symmetry

I'm sorry but your answers do not make sense.

Can you help me?

As the circle rolls there is always a distance equal to the radius between the edge of the circle and the center. So what is the position of the center of the circle as it rolls on a horizontal surface?

Hint: The answer is in the statement above. If you aren't seeing it, you are thinking about the problem too hard. If it helps, take a can and roll it on a table and see what the center of the can does.

-Dan

Originally Posted by symmetry

I'm sorry but your answers do not make sense.

Can you help me?

I thought the diagram made it pretty clear

Did you try moving the red point (just click and drag, and the circle will roll across the "table")

Dan,

I guess the answer is right in the question.

Thanks!

Originally Posted by symmetry

Dan,

I guess the answer is right in the question.

Thanks!

I want to make sure you've got it. What is your equation for the center of the circle?

-Dan

Thank you all for your replies.

To Quick:

Your diagram never appeared with in the reply.

To Dan:

The equation is y = 2 because the center of the circle makes no vertical movement, right?

Originally Posted by symmetry

To Quick:

Your diagram never appeared with in the reply.

Can you still not see it?

What browser are you using?

I got it and answered my own question thanks to the hints.