Regarding the rotation of the Earth about its axis:

$A$ body rotates about a stationary axis. If the angular deceleration is proportional to the square root of the angular speed, then the mean angular speed of the body, given $\omega_0$ as the initial angular speed, is

The spool shown in the figure is placed on a rough horizontal surface and has an inner radius $r$ and an outer radius $R$. The angle $\theta$ between the applied force and the horizontal can be varied. The critical angle $\theta$ for which the spool does not roll and remains stationary is given by:

What is the direction of angular velocity in circular motion about a fixed axis of rotation?

For a particle,the angular velocity is $\vec{\omega} = \hat{i} - 2\hat{j} + 3\hat{k}$ and the position vector is $\vec{r} = \hat{i} + \hat{j} + \hat{k}$. What is the linear velocity $\vec{v}$?

$A$ small particle of mass $m$ is given an initial high velocity in the horizontal plane and winds its cord around the fixed vertical shaft of radius $a$. All motion occurs essentially in the horizontal plane. If the angular velocity of the cord is $\omega_0$ when the distance from the particle to the tangency point is $r_0$,then the angular velocity of the cord $\omega$ after it has turned through an angle $\theta$ is