Paddling a canoe demonstrates which law?

Paddling a canoe demonstrates which law?

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

Answer: (D)

Paddling a canoe demonstrates Newton's Third Law of Motion: for every action, there is an equal and opposite reaction. When you push the paddle backward against the water, you exert a backward force on the water. In turn, the water pushes the paddle (and the canoe through the paddle) forward with an equal and opposite force. This forward push propels the canoe across the water. The key idea is the action-reaction pair at the water–paddle interface: the water responds to your push with a forward thrust that moves the boat. While other laws can describe aspects of what happens, they aren’t the direct mechanism at work here. Inertia is about resisting changes in motion, which explains why the canoe would keep moving once it’s going, but not how you generate forward motion. Gravity governs vertical forces and weight, not the propulsion along the water. Newton’s Second Law relates net force to acceleration, which is relevant to how fast you speed up, but the propulsion effect you observe comes from the action-reaction pair described by the Third Law.

Paddling a canoe demonstrates Newton's Third Law of Motion: for every action, there is an equal and opposite reaction. When you push the paddle backward against the water, you exert a backward force on the water. In turn, the water pushes the paddle (and the canoe through the paddle) forward with an equal and opposite force. This forward push propels the canoe across the water. The key idea is the action-reaction pair at the water–paddle interface: the water responds to your push with a forward thrust that moves the boat.

While other laws can describe aspects of what happens, they aren’t the direct mechanism at work here. Inertia is about resisting changes in motion, which explains why the canoe would keep moving once it’s going, but not how you generate forward motion. Gravity governs vertical forces and weight, not the propulsion along the water. Newton’s Second Law relates net force to acceleration, which is relevant to how fast you speed up, but the propulsion effect you observe comes from the action-reaction pair described by the Third Law.