Rolling Rolling
Two circles of equal radii touch at the point say at P. One circle is fixed whilst the other moves, rolling without slipping, all the way round. How many times does the moving circle revolve before returning to P?
Drag the slider 'a' to move the green circle.
What happens if the radius of the moving circle is half that of the fixed circle?
Drag the slider 'a' to move the green circle.
Can you generalise it? Key question: How far does the centre of the rolling disk travel?