1. Newton’s Third Law

2. And it states…
For every (action) force, there is an equal (reaction) force in the opposite direction on the object that applied the force by whatever the force was applied to.
In short: For every action there is an equal and opposite reaction.
This has nothing to do with human nature or philosophy!

3. It means… If you punch someone in the face…
It does not mean they will stand up and punch you back!!! (they could just sit there and cry, or run away!)
It means their face hits your hand with the same force your hand hit their face!
Which is why so many guys get broken hands in a fight!!

4. Major misconception
The action and reaction force are NOT on the same object!
Action is on the object the force is applied to.
Reaction is on what applied the force.
If you kick a ball …
action force on the ball from your foot
reaction force on your foot from the ball

5. Force Diagram Force on the ball from These forces are your foot
equal in magnitude
(strength)
Causing
a change in
motion sending
it forward
And opposite in
direction.
Causing a change
in motion slowing
down your foot
Force on
your foot
from the ball

6. All Motion Depends On This Law
How do you walk?
You push on the ground backward; the ground pushes you forward.
How do you swim?
You push the water back; the water pushes you forward.

7. Motion in Outer Space
It’s a vacuum — there is nothing there. No air of any kind.
If you want to move, you had better bring something with you to throw out the back!
Spaceships bring oxygen and hydrogen, and ignite them in the back of their ships.
This sends water vapor flying in the opposite direction and pushes them forward.
They call it a burn on the movies (and in mission control)