Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that whenever an object exerts a force on another object, the second object exerts an equal and opposite force on the first object. In simpler terms, if object A pushes or pulls on object B, object B pushes or pulls back on object A with the same magnitude but in the opposite direction.
This law highlights the idea that forces always occur in pairs. These force pairs act on different objects and have equal magnitudes but opposite directions. It is important to note that these forces do not cancel each other out because they act on different objects.
This law is relevant in various everyday situations, such as when a person walks. When a person takes a step forward, their foot exerts a backward force on the ground (action), and the ground exerts an equal and opposite forward force on the foot (reaction), propelling the person forward.