$A$ body of mass $m$ moving with speed $3 \ m/s$ collides with a body of mass $2m$ at rest. The coalesced mass will start to move with a speed of (in $m/s$)

$A$ body of mass $20 \ kg$ moving with a speed of $10 \ m/s$ collides with a stationary body of mass $5 \ kg$. After the collision,both bodies stick together. The combined kinetic energy of the system will be $...... \ J$.

Ball $A$ of mass $1 \,kg$ moving along a straight line with a velocity of $4 \,ms^{-1}$ hits another ball $B$ of mass $3 \,kg$ which is at rest. After collision, they stick together and move with the same velocity along the same straight line. If the time of impact of the collision is $0.1 \,s$, then the force exerted on $B$ is (in $\,N$)

$A$ body of mass $40\,kg$ having velocity $4\,m/s$ collides with another body of mass $60\,kg$ having velocity $2\,m/s$. If the collision is perfectly inelastic, then the loss in kinetic energy will be .............. $J$.

$A$ 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 $g = 10 \text{ m/s}^2$)

$A$ particle of mass $m$ moving with velocity $v$ collides with a stationary particle of mass $2m$ and sticks to it. What will be the speed of the system?