When two bodies stick together after collision,the collision is said to be

$A$ particle of mass $m$ moving eastward with a speed $v$ collides with another particle of the same mass moving northwards with the same speed $v$. The two particles coalesce on collision. The new particle of mass $2m$ will move with velocity:

$A$ body of mass $m$ moving with a constant velocity $v$ hits another body of the same mass that is at rest. If the two bodies stick together after the collision,the velocity of the compound body is:

$A$ metal ball of mass $2 \,kg$ moving with a velocity of $36 \,km/h$ has a head-on collision with a stationary ball of mass $3 \,kg$. If after the collision,the two balls move together,the loss in kinetic energy due to the collision is ........ $J$.

$A$ 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

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