FORCE AND LAWS OF MOTION question bank (Science)

Two objects of masses $100 \, g$ and $200 \, g$ are moving along the same line and direction with velocities of $2 \, m \, s^{-1}$ and $1 \, m \, s^{-1}$,respectively. They collide and after the collision,the first object moves at a velocity of $1.67 \, m \, s^{-1}$. Determine the velocity (in $m/s$) of the second object.

Two objects,each of mass $1.5\, kg$,are moving in the same straight line but in opposite directions. The velocity of each object is $2.5\, m/s$ before the collision during which they stick together. What will be the velocity (in $m/s$) of the combined object after collision?