For every action, there is an equal and opposite reaction.

This means that:

* Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object.

Example:

Imagine you are pushing a box. You are applying a force to the box (action), and the box is pushing back on you with an equal and opposite force (reaction). This is why you feel resistance when you push the box.

Here are some other examples:

* When you jump, you push down on the ground (action), and the ground pushes back up on you (reaction), propelling you into the air.

* When a rocket launches, it expels hot gases downward (action), and the gases push back on the rocket, propelling it upward (reaction).

* When a swimmer pushes against the water (action), the water pushes back on the swimmer (reaction), propelling them forward.

Key Points:

* The forces are always equal in magnitude and opposite in direction.

* The forces act on different objects.

* The forces occur simultaneously.

Applications:

Newton's Third Law has many applications in science and engineering, including:

* Understanding how rockets work

* Designing airplanes and cars

* Developing new materials

This law is fundamental to understanding the interactions between objects in the universe.