Final answer:
The example of a gun firing a dart and experiencing a recoil force in the opposite direction exemplifies Newton's Third Law of Motion, which states that forces between two interacting bodies are equal in magnitude and opposite in direction.
Step-by-step explanation:
When a gun fires a dart, and both the dart and the gun experience forces in opposite directions, this demonstrates Newton's Third Law of Motion. This law states that whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that it exerts. An example that illustrates this concept is the recoil felt when firing a gun: the force propelling the dart forward is matched by an equal force pushing the gun backward.
Newton's Third Law of Motion can also be observed in rockets. As the rocket expels gases backward, it experiences a thrust forward because the gases exert an equal and opposite force. This illustrates how actions and reactions work without the need to push against air or another surface, allowing rockets to function effectively in space, which is a vacuum.
This law can be mathematically represented as FAB = -FBA, indicating the forces on two interacting bodies (A and B) are equal in magnitude and opposite in direction, creating what we know as an action-reaction pair.