$A$ body of mass $m$ moving with a constant velocity $v$ hits another body of the same mass that is at rest. If the two bodies stick together after the collision,the velocity of the compound body is:

$A$ particle of mass $m_1$ undergoes a perfectly inelastic head-on collision with another particle of mass $m_2$ at rest $(m_2 > m_1)$. What fraction of the initial kinetic energy is converted into heat energy during this collision?

$A$ 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 ........

$A$ particle of mass $m$ moves with velocity $v$ towards the East. It collides with another particle of the same mass and same speed moving towards the North and sticks to it. What will be the velocity of the combined particles?

$A$ mass of $20\, kg$ moving with a speed of $10\, m/s$ collides with another stationary mass of $5\, kg$. As a result of the collision,the two masses stick together. The kinetic energy of the composite mass will be ............. $J$.

Two balls of masses $m$ each are moving at right angles to each other with velocities $6 \, m/s$ and $8 \, m/s$ respectively. If the collision between them is perfectly inelastic,the velocity of the combined mass is ......... $m/s$.