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Newton’s third law of motion definition

To every action, there is always an equal and opposite reaction.

Examples of Newton’s third law of motion

1. If we place our hand on the table and press it hard in the downward direction, we feel that table is exerting a force on our hand In the upward direction. The force exerted by hand on the table is called action whereas the push of the table on our hand is called reaction.
2. Consider a book of weight w which is placed on a horizontal table. It pushes the table with a force W in the downward direction. This is the action of the book on the table. In response to this action, the table also pushes the book in the upward direction. Since the book is at rest. The resultant force F acting on the body must be zero that is:

Forces acting on the body

a) The force of gravity acting downward which we call the weight of the book.
b) The other force is the push of the table on the book in the upward direction
These two forces are equal and opposite to keep the book in its stationary condition
Example (Rocket)
In the engine of a rocket, gases due to combustion rush out with great speed through jet on the backside of the rocket and as a reaction, the rocket moves in the upward direction
It is clear that action and reaction always occur together as a pair and act on different bodies.

Related Topics:

• How many types of motion are there in Physics?
• Equations of motion
• What are the three laws of motion?
• Examples of force
• Branches of Physics
• Difference between distance and displacement
• Newton first law
• Newton’s second law