These are equal and opposite forces that do not cause a change in position or motion.

Balanced forces.

Explanation:

Forces that are opposite in direction, and, equal in size do not cause a change in motion or position are known as balanced forces. When it is applied to an object at rest, the object will not show any movement.

A good example of a balanced force is when we are trying to push a wall, the wall will push back with an opposite but equal force, so, this time neither the wall nor you will move.

moving ball hits still ball. mover stops, hit ball moves. momentum transfer.

where are the vectors ?