$A$ 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 $... \ J$.

$A$ body of mass $5\,kg$ strikes another body of mass $2.5\,kg$ initially at rest. The bodies after collision coalesce and begin to move as a whole with a kinetic energy of $5\,J$. The kinetic energy of the first body before collision is ............... $J$.

$A$ bullet of mass $m$ moving horizontally with speed $v_0$ hits a wooden block of mass $M$ that is suspended from a massless string. The bullet gets lodged into the block. If the block-bullet system swings to a maximum height $h$,how much of the initial kinetic energy of the bullet is lost in the collision?

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?

The coefficient of restitution $e$ for a perfectly inelastic collision is

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 $ms^{-1}$.