A cannonball shot forward and the cannon moves back demonstrates which law?

A cannonball shot forward and the cannon moves back demonstrates which law?

• A. Newton's Second Law of Motion
• B. Newton's Third Law of Motion
• C. The Law of Inertia
• D. Law of Universal Gravitation

Answer: (B)

When two objects interact, they exert equal and opposite forces on each other. Here, the expanding gases push the cannonball forward, and the cannon experiences an equal and opposite push backward. These two forces form an action-reaction pair that act on two different bodies at the same time. This is Newton's Third Law in action. Because the cannon is much heavier than the cannonball, the backward push gives the cannon only a small recoil, while the ball gains a large forward speed. The situation also fits momentum conservation for the system, assuming negligible external forces. The other ideas don’t capture the actual interaction: inertia is about resistance to motion change, gravity isn’t about this internal interaction, and while forces cause accelerations (Second Law), the hallmark here is the paired action and reaction.

When two objects interact, they exert equal and opposite forces on each other. Here, the expanding gases push the cannonball forward, and the cannon experiences an equal and opposite push backward. These two forces form an action-reaction pair that act on two different bodies at the same time. This is Newton's Third Law in action. Because the cannon is much heavier than the cannonball, the backward push gives the cannon only a small recoil, while the ball gains a large forward speed. The situation also fits momentum conservation for the system, assuming negligible external forces. The other ideas don’t capture the actual interaction: inertia is about resistance to motion change, gravity isn’t about this internal interaction, and while forces cause accelerations (Second Law), the hallmark here is the paired action and reaction.