Two particles $A$ and $B$ initially at rest move towards each other under a mutual force of attraction. At the instant when velocity of $A$ is $v$ and that of $B$ is $2v$, the velocity of centre of mass of the system :

In a rectangle $ABCD (BC = 2AB)$. The moment of inertia will be minimum along the axis :-

Five masses each of $2\, kg$ are placed on a horizontal circular disc, which can be rotated about a vertical axis passing through its centre and all the masses be equidistant from the axis and at a distance of $10\, cm$ from it. The moment of inertia of the whole system (in $gm-cm^2$ ) is: (Assume disc is of negligible mass)

Two points of a rigid body are moving as shown. The angular velocity of the body is: ?

In the following figure $r_1$ and $r_2$ are $5\,cm$ and $30\,cm$ respectively. If the moment of inertia of the wheel is $1500\,kg\,m^2$ then its angular acceleration will be (Approximately) 

A uniform rod of mass $m$ and length $l$ rotates in a horizontal plane with an angular velocity $\omega $ about a vertical axis passing through one end. The tension in the rod at a distance $x$ from the axis is