Add new comment

Permalink

The question without the accompanying diagram could also mean to roll the small circle within the larger one. If this is done you actually lose a rotation. The answer then is 3!
The easiest way to calculate the rotations is to use the path taken by the centre of the small circle.
If r[1] = radius of small circle; r[2] = radius of path outside and r[3] = radius of path inside the large circle then:-
Rotations outside = (2 x pi x r[2])/(2 x pi x r[1]) = (2 x pi x 5)/(2 x pi x 1) = 5/1 = 5.
Rotations inside = (2 x pi x r[3])/(2 x pi x r[1]) = (2 x pi x 3)/(2 x pi x 1) = 3/1 = 3.

K. Selby

Filtered HTML

  • Web page addresses and email addresses turn into links automatically.
  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.