The angular speed of the seconds needle in a mechanical watch is:

Check the only correct statement in the following:

$A$ fan is making $600$ revolutions per minute. If after some time it makes $1200$ revolutions per minute,then the increase in its angular velocity 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 $2 \,min \,20 \,s$?

Two cars of masses $m_{1}$ and $m_{2}$ are moving in circles of radii $r_{1}$ and $r_{2}$ respectively. Their angular speeds $\omega_{1}$ and $\omega_{2}$ are such that they both complete one revolution in the same time $t$. The ratio of the linear speed of $m_{1}$ to the linear speed of $m_{2}$ is:

If a body is moving in a circle of radius $r$ with a constant speed $v$,its angular velocity is: