if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.
There are equal forces upon objects
B
Momentum conservation:
For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That is, the momentum lost by object 1 is equal to the momentum gained by object 2.
F1=-F2
T1=T2
C
An isolated system is a system that F is free from the influence of a net external force that alters the momentum of the system. There are two criteria for the presence of a net external force; it must be...
a force that originates from a source other than the two objects of the system
a force that is not balanced by other forces.
only forces that contribute to the momentum change of an individual object are the forces acting between the objects themselves can be considered an isolated system.