Consider two satellites $A$ and $B$ of equal mass $m$,moving in same circular orbit about earth. but in opposite as shown in figure. The orbital radius is $r$. The satellites undergoes a collision which is perfectly inelastic. Which is perfectly inelastic. For this situation , mark out the correct statements $\left(s\right)$. 

[Take mass of earth as $M$] 

Just before collision, the total energy of two satellites is , 

$E = -\frac{GMm}{2r} -\frac{GMm}{2r}-\frac{GMm}{r}$

Let orbital velocity is $v_1$ then from momentum conservation

$mv-mv=2m\times v_1 \Rightarrow v_1 =0$

As velocity of combined mass just after collision is zero, the combined mass will far towards earth. At this instant , the total energy of the system only consist of the gravitational potential energy given by $U =- \frac{GM \times 2m}{r}$