The action-reaction law, also known as Newton's third law of motion, states that for every action, there is an equal and opposite reaction. This law is a fundamental principle in physics and has important implications in understanding motion and forces.
When an object exerts a force on another object, the second object exerts an equal force in the opposite direction on the first object. This means that forces always occur in pairs.
For example, when you push against a wall, the wall pushes back on you with an equal force in the opposite direction. This is why you feel resistance when pushing against a solid object.
By mastering the action-reaction law, you'll gain a solid foundation in understanding the fundamental principles of motion and forces in the physical world.