The angular speed of the minute hand of a clock in degrees per second is

The length of the second's hand in a watch is $1 \, cm$. The change in velocity of its tip in $15 \, seconds$ is

$A$ wheel of radius $4 \, m$ completes one revolution in $2 \, s$. Find the centripetal acceleration of the wheel.

$A$ body moving in a circular path with a constant speed has constant:

Two particles having mass $M$ and $m$ are moving in a circular path with radius $R$ and $r$ respectively. The time period for both the particles is same. The ratio of angular velocity of the first particle to that of the second particle will be

The position vector of a particle is $\vec{r} = a \cos \omega t \hat{i} + a \sin \omega t \hat{j}$. Calculate the angle between its position vector and the velocity vector. $(\cos 0 = 1, \cos 90 = 0, \cos 60 = 0.5, \sin 30 = 0.5, \sin 0 = 0)$ (in $^\circ$)