Final answer:
In the strength of forces in a collision, equal strength but opposite directional forces act upon colliding objects, and changes in velocity post-collision are explained by momentum conservation.
Step-by-step explanation:
From the SIM about the strength of forces in a collision, we learn that when a collision occurs, forces of equal strength but in opposite directions are exerted on the colliding objects, by Newton's third law of motion. If two ice cubes, having the same mass and originally at rest, collide on a smooth surface, and one is flicked towards the other, the velocities and directions of the ice cubes post-collision can be explained by conservation of momentum. The force exerted during the collision changes the velocity of each ice cube, with the direction of this force being dependent on the movement and contact during the collision.