# Rolling Question

## Homework Statement

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 ??

Last edited:

Related Introductory Physics Homework Help News on Phys.org
rock.freak667
Homework Helper
Constant angular velocity means that the angular acceleration is zero. So the tangential acceleration is zero.

so the question means i should get the tangent acceleration right not the radial one ?

rock.freak667
Homework Helper
so the question means i should get the tangent acceleration right not the radial one ?
$$a_t = \alpha r$$

$$a_r = \frac{v^2}{r}$$

seeing as that $\alpha=0$, which one do you think you should find?

$$a_t = \alpha r$$

$$a_r = \frac{v^2}{r}$$

seeing as that $\alpha=0$, which one do you think you should find?
lol ,, got it :) ,, thanks ,, exam questions are so poor -_-