It's not only thick people who have trouble understanding Newton's laws. But although they appear complicated, they are actually very simple. However, first we must get to know four scientific terms:

Force: When you kick your sister in the shin, you are using force.

Mass: If she is fat she has lots of mass.

Inertia: Being fat, she will not be able to chase you. She has inertia.

Energy: Every time you kick her, molecules in the form of waves pass from your foot to her shin. This is energy. There can be lots of energy, like a nuclear bomb, or a tiny amount, like when one of your brain cells dies.

Newton's First Law

If something is not moving it will stay where it is.

Kick your sister in the shins. Go on, do it now. You will see that she reacts.

Let's just think about what happened there. If you hadn't kicked her, she would have stayed where she was, probably sitting in front of the telly eating cakes. Hence, the first law is proved.

Newton discovered this law when an apple fell on his head. To this day it is know as Newton's Apple Law.

Newton's Second Law

Every action results in a small loss of energy.

You know how when you do a lot of exercise, you run out of breath? Well, this is proof of Newton's second law. This may seem simple but it has terrible consequences for the universe. You see, if the universe runs out of energy soon, everyone in it, including you and your family, will just waste away into nothing! But don't worry too much — scientists don't think this will happen in your lifetime.

Newton's Third Law

Mass and Energy are interchangeable, and vice-versa.

Sound confusing? It's not really!

Let's imagine you are on a roller coaster, with your sister. Perhaps you are in Disney World. Now let's say the track is buckled and the wheels come off. When your car hits the ground the energy it makes is equivalent to your mass — and with your sister in the car with you, this is bad news for both of you.

Conversely, if you push your sister in front of you, and then clamber aboard her as she hurtles to the ground, Newton's Third Law states that she will absorb all the impact, and you will survive. So, you see — a sound knowledge of science may one day save your life!