Answered on
The third law of motion, formulated by Sir Isaac Newton, is often stated as: "For every action, there is an equal and opposite reaction." This law means that for every force exerted by one object on another, there is an equal force exerted in the opposite direction by the second object on the first. In other words, forces always come in pairs, acting on two different objects and never exist in isolation. The size of the forces on the first object and the second object is always exactly the same (equal in magnitude) but they act in opposite directions.
Newton's third law of motion is a fundamental principle that helps us understand how objects interact with each other. It applies to all types of forces and all kinds of interactions, and it is essential for analyzing the motion of objects. For example, when you sit in a chair, your body exerts a downward force on the chair due to gravity, and the chair exerts an upward force on your body that is equal in magnitude but in an opposite direction, allowing you to remain at rest.
The third law can also explain how we walk or swim. As you push your foot backward against the ground, the ground pushes forward on your foot with an equal and opposite force, propelling you forward. Similarly, when swimming, as you push water backwards, the water pushes you forward. This principle is also what allows rockets to fly. Rockets work by expelling exhaust gases backward at high speed; the reaction to this action is that the rocket is propelled forward.
Understanding the third law of motion is crucial in engineering, physics, and many other fields because it allows for the prediction of the behavior of objects under the influence of various forces. It also helps in designing stable structures, understanding the dynamics of systems, and solving mechanical problems.