Two bodies $A$ and $B$ are attracted towards each other (beginning at rest) due to gravitation. Given that $A$ is much heavier than $B$, which of the following correctly describes the motion of the centre of mass of the bodies?

Two particles $A$ and $B$ of equal mass are projected simultaneously with speed $10 \mathrm{m} {\mathrm{s}}^{-1}$ each as shown in figure. Find the co-ordinate of COM at $t=10 \mathrm{s}$. (Take, $g=10 \mathrm{m} {\mathrm{s}}^{-1}$)

Two masses $m_1=4\mathrm{kg}$ and $m_2=2\mathrm{kg}$ are released from rest as shown in figure. 

Find the distance $\left(\mathrm{in} \mathrm{m}\right)$  travelled by centre of mass in $9 \mathrm{s}$.

Two masses $m_1=4\mathrm{kg}$ and $m_2=2\mathrm{kg}$ are released from rest as shown in figure. Find the speed of the centre of mass after $9 \mathrm{s}$ in $\mathrm{m} {\mathrm{s}}^{-1}$.

From a square sheet of uniform density, a portion is removed shown as shaded region in the figure. Find the centre of mass of the remaining portion if the side of the square is $a$.

A uniform circular disc of radius '$a$' is taken. A circular portion of radius '$b$' has been removed from it as shown in figure. If the centre of hole is at a distance '$c$' from the centre of the disc, the distance $x_2$ of the centre of mass of the remaining part from the initial centre $O$ is given by:

Find the velocity of centre of mass if the triangle formed is equilateral.