Which law describes the interaction forces when two objects push on each other with equal magnitude in opposite directions?

Which law describes the interaction forces when two objects push on each other with equal magnitude in opposite directions?

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

Answer: (C)

When two objects push on each other, the forces they exert form equal and opposite pairs that act on the two different objects. This is action and reaction: the force on one object is the same magnitude as the force on the other, but in the opposite direction. Because they act on different bodies, these forces don’t cancel each other out; each object responds to the net force it experiences and may accelerate accordingly. For example, pushing against a wall yields a back force from the wall of the same strength in the opposite direction, which is why you can push off and move away. In space, two astronauts pushing off each other fly apart in opposite directions with equal forces. Other laws describe how a single object moves under net forces (not the interaction between two objects) or describe motion when no net force acts, so they don’t capture the idea of equal-and-opposite interaction forces between two bodies.

When two objects push on each other, the forces they exert form equal and opposite pairs that act on the two different objects. This is action and reaction: the force on one object is the same magnitude as the force on the other, but in the opposite direction. Because they act on different bodies, these forces don’t cancel each other out; each object responds to the net force it experiences and may accelerate accordingly.

For example, pushing against a wall yields a back force from the wall of the same strength in the opposite direction, which is why you can push off and move away. In space, two astronauts pushing off each other fly apart in opposite directions with equal forces.

Other laws describe how a single object moves under net forces (not the interaction between two objects) or describe motion when no net force acts, so they don’t capture the idea of equal-and-opposite interaction forces between two bodies.