Question

Two bodies collide with each other in an inelastic manner. After the collision, both the bodies come to rest. Which of the following statements is true?

• A. Both the bodies were initially moving in the same direction.
• B. Both the bodies were initially moving in the opposite direction.
• C. One of the bodies was initially at rest.
• D. None of the above statements are true.

Answer 1

The correct option is B Both the bodies were initially moving in the opposite direction.

During the collision between the two bodies the impulsive forces acting on them becomes internal force for the system of colliding bodies i.e $F_{ext}=0$, hence the linear momentum of the system remains conserved.

The final momentum of the system is zero (both the bodies come to rest after collision). This is only possible when the initial momentum of the two bodies were in the opposite directions i.e. the velocities of the two bodies were in opposite directions.
Hence the correct option is (b).