The Grand Finale - Newton's Third Law of Motion

Now we've come to Newton's last law of motion. This one's pretty simple to be honest. Here it is:




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

Yoshi knows his physics!

It's quite short, isn't it. The definitions short and simple too, whenever a force acts (a push or a pull - the action), then another force acts in the opposite direction with exactly the same amount of force (what we call the reaction force. So when you punch a wall, the wall punches back and that's why you're hand doesn't move: the wall is pushing back with an equal force. But what if your hand goes through the wall I hear you ask? Well, that's the clever bit. Since there's no more force to support the wall the ground pushes the opposite way to account for the remaining force and so you topple over as your feet are pushing one way, your arms are moving in the other.
Another example is in a tug of war. When you pull on the rope you have to dig your feet into the ground to stop yourself falling over. You wouldn't be able to do it on ice! So when you pull your feet push the other way with an equal force.
You can see this if you step onto one of those really small boats. Try and walk forwards and you'll find the boat moves backwards. This is because your feet are pushing the other way!
If you have any questions please let me know in the comments :D!