Third Law Of Motion

key notes :

Introduction:

  • Sir Isaac Newton, a renowned physicist, formulated three fundamental laws of motion.
  • The Third Law of Motion is one of these laws and is also known as Newton’s Third Law.

Newton’s Third Law:

  • Newton’s Third Law states, “For every action, there is an equal and opposite reaction.”
  • This law means that when an object exerts a force on another object (action), the second object exerts an equal force in the opposite direction (reaction).

Key Points:

  1. Action and Reaction Pairs:
  • Forces always occur in pairs – one is the action, and the other is the reaction.
  • If object A exerts a force on object B, object B exerts an equal and opposite force on object A.
  1. Balanced Forces:
  • Action and reaction forces do not cancel each other out because they act on different objects.
  • They can, however, result in balanced forces, causing no acceleration.
  1. Examples:
  • Jumping off a diving board: When you push down on the board (action), it pushes you upward into the air (reaction).
  • Walking: Your foot pushes backward on the ground (action), and the ground pushes your foot forward (reaction), propelling you forward.
  1. Rocket Propulsion:
  • Rockets work based on Newton’s Third Law. The engine expels high-speed exhaust gases (action), and in response, the rocket moves in the opposite direction (reaction).
  1. Everyday Applications:
  • Newton’s Third Law can be observed in many daily activities, from walking and swimming to driving a car or riding a bicycle.

Conclusion:

  • Understanding Newton’s Third Law helps explain the fundamental principle of action and reaction in the physical world.
  • It is a crucial concept in physics, explaining how objects move and interact with each other.
  • This law has practical applications in various fields, including engineering, aviation, and space exploration.

Summary:
Newton’s Third Law of Motion states that every action has an equal and opposite reaction. It means that when one object exerts a force on another, the second object exerts an equal force in the opposite direction. This law is fundamental to understanding how objects move and interact in the physical world and has practical applications in many aspects of our lives.

Let’s practice!