$A$ particle of mass $m_1$ moving with a velocity of $5 \ m/s$ undergoes a head-on collision with a stationary particle of mass $m_2$. After the collision,both particles move with a common velocity of $4 \ m/s$. Find the ratio $m_1/m_2$.

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 $ms^{-1}$.

Which of the following is not an example of a perfectly inelastic collision?

$A$ bag of mass $M$ is suspended by a long string. $A$ bullet of mass $m$ moving with velocity $v$ hits the bag and gets embedded in it. For the (bag + bullet) system:

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:

$A$ 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 ........ $J$.