$A$ body of mass $20 \ kg$ moving with a velocity of $10 \ m/s$ collides with a stationary body of mass $5 \ kg$ and sticks to it. The combined kinetic energy of the system after the collision is . . . . . . $J$.

$A$ 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 ........

In perfectly inelastic collisions,the relative velocity of the bodies

$A$ particle of mass $m$ moving towards west with speed $v$ collides with another particle of mass $m$ moving towards south. If the two particles stick to each other,the speed of the new particle of mass $2m$ will be ..........

$A$ body of mass $1 \ g$ moving with a velocity of $3\hat{i} - 2\hat{j} \ m/s$ collides with a body of mass $2 \ g$ moving with a velocity of $4\hat{j} - 6\hat{k} \ m/s$. If the two bodies stick together after the collision,what is the magnitude of their combined velocity in $m/s$?

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