Head-on Collision:
* Conservation of Momentum: In a head-on collision, the momentum of the moving ball is transferred to the stationary ball. Momentum is the product of mass and velocity.
* Equal and Opposite Forces: The forces between the balls act along the same line. Since the forces are equal and opposite (Newton's Third Law), the moving ball's momentum is completely transferred.
* Energy Loss: The collision isn't perfectly elastic. Some energy is lost as heat, sound, and deformation of the balls. This loss of energy means the moving ball will have less kinetic energy after the collision and will therefore come to a stop.
Non-Head-on Collision:
* Angular Momentum: When the collision is not head-on, the impact is off-center. This creates a transfer of angular momentum – a measure of an object's tendency to rotate. The moving ball will spin, and the stationary ball will also gain some rotational motion.
* Direction Change: The moving ball doesn't simply transfer its linear momentum to the stationary ball. Instead, the momentum is transferred in different directions, causing the moving ball to change direction.
* Continued Motion: Because of the angular momentum and direction change, the moving ball retains some of its linear motion and doesn't come to a complete stop.
In short: In a head-on collision, the energy transfer is efficient, leading to the moving ball coming to a stop. In a non-head-on collision, energy is transferred into rotational motion and direction change, causing the moving ball to continue its movement.
