If ${a_r}$ and ${a_t}$ represent radial and tangential accelerations,the motion of a particle will be uniformly circular if

If $\vec{L}$ and $\vec{P}$ represent the angular momentum and linear momentum respectively of a particle of mass $m$ having position vector $\vec{r} = a(\hat{i} \cos \omega t + \hat{j} \sin \omega t)$,the direction of the force acting on the particle is:

Which of the following quantities remains constant during uniform circular motion?

The displacement of a body when it covers a distance of $C / 4$ (where,$C$ is circumference) along the circumference of a circle of radius $r$ with a uniform speed $u$ is

An athlete completes one round of a circular track of radius $R$ in $40 \,s$. What will be his displacement at the end of $2 \,min \,20 \,s$?

What is the physical quantity represented by the unit $rpm$? Express it in $rad/s$.