Seeing the pair
Two situations in which an action–reaction pair can be seen with your own eyes.
Air escaping from a balloon
Figure to be added
Hold an air-filled balloon in your hand with its mouth turned downwards. Now loosen the mouth and let go. The balloon can be seen shooting upwards before falling to the ground.
| Applied by | Applied to | |
|---|---|---|
| Action | The balloon's rubber walls | The air particles — downwards |
| Reaction | The escaping air particles | The balloon — upwards |
The balloon does not rise with nothing pushing it — the escaping air is what pushes it.
Try it on a wire
Attach an air-filled balloon to a drinking straw with pieces of sellotape, thread a wire through the straw, and hold the wire horizontally at both ends. Now loosen the mouth of the balloon.
The balloon can be seen travelling along the wire in the direction opposite to the way the air escapes.
Two children
Figure to be added
Place two boards on several glass balls and seat two people on them. If they then put palm against palm and push each other, both will be pushed away in opposite directions.
Even if only one of them pushes
If only one child pushes, both still move. The one doing the pushing gets an equal push back — which is the third law itself.