In a perfectly inelastic collision,what happens to the two colliding particles after the collision?

Two bodies of the same mass $m$ are moving with the same speed $v_0$,but in different directions in a plane. They undergo a completely inelastic collision and move together thereafter with a final speed which is half of their initial speed. The angle between the initial velocities of the two bodies (in degrees) is:

Two cars of equal mass $m$ moving with the same speed $v$ undergo a perfectly inelastic collision. What is the velocity of the combined mass after the collision?

Two particles of equal mass $m$ have respective initial velocities $u\hat{i}$ and $u\left(\frac{\hat{i}+ \hat{j}}{2}\right)$. They collide completely inelastically. The energy lost in the process is

$A$ body of mass $m$ moving along a straight line collides with a stationary body of mass $2m$. After collision,if the two bodies move together with the same velocity,then the fraction of kinetic energy lost in the process is

$A$ bullet of mass $m$ moving with a speed $v$ strikes a wooden block of mass $M$ and gets embedded into the block. The final speed is