Which law best explains the recoil you feel when you push off from a raft?

Which law best explains the recoil you feel when you push off from a raft?

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

Answer: (D)

The recoil you feel comes from action–reaction forces in Newton's Third Law: for every force there is an equal and opposite force in the opposite direction. When you push on the raft, your hands push the raft forward. In response, the raft pushes your hands backward with the same magnitude. That opposite force on you is what makes you move backward, i.e., recoil, while the raft moves forward. The two forces are part of the same interaction and act at the same time, which is why you feel a backward push when you push off. Inertia is about resisting changes in motion, and Newton’s Second Law links net force to acceleration for a single object, but neither by itself explains why the force you exert has a matching opposite force on you. The Law of Universal Gravitation isn’t involved in this horizontal push-off.

The recoil you feel comes from action–reaction forces in Newton's Third Law: for every force there is an equal and opposite force in the opposite direction. When you push on the raft, your hands push the raft forward. In response, the raft pushes your hands backward with the same magnitude. That opposite force on you is what makes you move backward, i.e., recoil, while the raft moves forward. The two forces are part of the same interaction and act at the same time, which is why you feel a backward push when you push off.

Inertia is about resisting changes in motion, and Newton’s Second Law links net force to acceleration for a single object, but neither by itself explains why the force you exert has a matching opposite force on you. The Law of Universal Gravitation isn’t involved in this horizontal push-off.