reaktsioonijõudu

Reaktsioonijõud is a fundamental concept in physics, specifically within Newton's laws of motion. It describes the force that is equal in magnitude and opposite in direction to the action force. This principle is often referred to as Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

When one object exerts a force on a second object, the second object simultaneously exerts a force back on the first object. These two forces, the action and the reaction, always occur in pairs and are always equal in strength but act in opposite directions. It is crucial to understand that these forces act on different objects. For instance, if you push on a wall, the wall pushes back on you with the same force. This is why you don't move through the wall.

The concept of reaction force is essential for understanding a wide range of phenomena, from the propulsion of rockets to the movement of a person walking. When a rocket expels gas downwards (action force), the expelled gas pushes the rocket upwards (reaction force), causing it to ascend. Similarly, when you walk, your foot pushes backward on the ground (action force), and the ground pushes forward on your foot (reaction force), propelling you forward. Without reaction forces, many everyday actions and natural processes would be impossible.