The relation between the linear speed and angular speed of particle of rotation motion is $v=r \omega$, where $r$ is the radius of circular path.

In general by any instant

$v_{i}=r_{i} \omega$ where $i=1,2,3, \ldots, n$ and $n$ is the no. of particles in the rigid body.

If $r=0, v=0$, means particles on axis are stationary.

For obtaining the relation between linear velocity and angular velocity, a particle $P$ of a rigid body rotating about $Z$-axis (fixed) as shown in figure. The position vector $\overrightarrow{O P}=\vec{r}$ of particle at $P$ on the rigid body with respect to the origin $\mathrm{O}$. Its perpendicular distance is $r_{1}$ from the centre $\mathrm{C}$ circular path.