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

$A$ body of mass $m$ moving with a constant velocity $v$ hits another body of the same mass moving with the same velocity $v$ but in the opposite direction and sticks to it. The velocity of the compound body after collision is

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

$A$ bag of mass $M$ is suspended by a string. $A$ bullet of mass $m$ moving with velocity $v$ enters the bag and gets embedded in it. Then,for the system:

$A$ bullet strikes against a wooden block and is embedded in it,the nature of collision is

$A$ block of mass $10 \text{ g}$ is suspended from the ceiling by a string. $A$ bullet of mass $10 \text{ g}$ moving with a velocity of $1 \text{ m/s}$ strikes the block and gets embedded in it. To what height will the block rise (in $\text{ cm}$)? (Take $g = 10 \text{ m/s}^2$)