Question

What is Angular Position?

Answer 1

To decide the angular position of a point in space we need to specify (i) origin and (ii) reference line. The angle made by the position vector w.r.t. origin, with the reference line is called angular position. Clearly angular position depends on the choice of the origin as well as the reference line.

Circular motion is a two dimensional motion or motion in a plane. Suppose a particle $\mathrm{P}$ is moving in a circle of radius $\mathrm{r}$ and centre $\mathrm{O}$. The angular position of the particle $\mathrm{P}$ at a given instant may be described by the angle $\theta$ between OP and OX. This angle $\theta$ is called the angular position of the particle.