Hi again ,, my second one is easy:
A tire 0.5 m in radius rotates at a constant rate of 200 rev/min. Find the speed and
acceleration of a small stone stuck on the surface of the tire (on its outer edge).
The Attempt at a Solution
the Speed of the rock is easy to get (W=200 rev/min = (20*pi)/3 rad/s = (10*pi)/3 m/s)
about the acceleration : should I get the tangent acceleration or the radial ??