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

$A$ moving body of mass $m$ and velocity $3 \, km/h$ collides with a body of mass $2m$ at rest and sticks to it. Now the combined mass starts to move. What will be the combined velocity in $km/h$?

$A$ bullet of mass $m$ strikes a block of mass $M$ connected to a light spring of stiffness $k$,with a speed $V_0$. If the bullet gets embedded in the block,then the maximum compression in the spring is

$A$ ball moving horizontally with a velocity $2 \,ms^{-1}$ strikes the bob of a seconds pendulum at rest. If the mass of the bob is equal to the mass of the ball and the collision is perfectly elastic, after collision the bob of the pendulum will raise to a height of $(g=10 \,ms^{-2})$ (in $\,cm$)

An object of mass $80 \,kg$ moving with velocity $2 \,ms^{-1}$ collides with another object of mass $20 \,kg$ moving with velocity $4 \,ms^{-1}$. Find the loss of energy assuming a perfectly inelastic collision. ........... $J$