6. using newtons third law and acceleration, explain why the motion of each of the balls changed.

Brief Explanations:

Newton's third law states that for every action, there is an equal and opposite reaction. When two balls interact (e.g., collide), the force exerted by one ball on the other is met with an equal - magnitude and oppositely - directed force. This force causes an acceleration according to Newton's second law ($F = ma$). The acceleration changes the velocity of each ball, thus changing its motion.

Answer:

The interaction between balls creates action - reaction forces. These forces cause accelerations that change the velocity and thus the motion of each ball.