Two masses of $0.25\, kg$ each move towards each other with speeds of $3\, ms^{-1}$ and $1\, ms^{-1}$. They collide and stick together. Find the final velocity in $ms^{-1}$.

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:

$A$ particle of mass $m$ moving with velocity $v$ collides with a stationary particle of mass $2m$. After collision,they stick together and continue to move together with velocity ........

$A$ body of mass $3 \ kg$ moving with a velocity $(2 \hat{i}+3 \hat{j}+3 \hat{k}) \ m/s$ collides with another body of mass $4 \ kg$ moving with a velocity $(3 \hat{i}+2 \hat{j}-3 \hat{k}) \ m/s$. The two bodies stick together after collision. The velocity of the composite body is

$A$ bullet of mass $a$ and velocity $b$ is fired into a large block of mass $c$. The final velocity of the system is

$A$ body of mass $40 \ kg$ moves with a velocity of $4 \ m/s$,and another body of mass $60 \ kg$ moves with a velocity of $2 \ m/s$. If they undergo a perfectly inelastic collision,the loss in kinetic energy is $... \ J$.