There are three of Isaac Newton's Laws. And there is only one more to show you, through zombies.
The last one is
Every action has an equal and opposite reaction.
This means that if you hit someone in the face, not only does your hand exert force on their face, but their face exerts another force right back at you. That's why it stings. The same thing applies to guns, as little Johnny Wembly is about to learn.
You see, Sergeant Smithson was a lazy soldier. He always tried to get other people to do his work. In this case, he assigned Johnny Wembly, a boy who is only 8 years old, to do his work.
Johnny was looking out at the barricade while, Smithson was sleeping.
When Johnny saw a zombie approach...
he fired his shot gun, and blew the ghoul to bits. What the boy did not realize was that the gun would the action of the gun would react on him.
"Ow!" Johnny cried as he fell on his rear, "you didn't tell me that would happen, Mister Smithson!!"
"You didn't ask. So, I didn't tell you," Said the sergeant, who just woke up.
"I was having a good dream too!" Smithson added, "did you have to make the gun that loud?"
Johnny only sighed.
And if Johnny ever learned Newton's laws in school, he would have a much better understanding of what had happened. And sometimes, it doesn't take a shredded skate boarder or a fool joining the ranks of the undead to get the point across. It can only take a bitter 8 year old, which can be a lot worse then a flesh eating zombie.
And remember... your science teacher may not seem like they know what they are talking about, but trust me... that information can come in handy when the apocalypse strikes!