Newton's Laws

Newton’s laws

One of the most famous physics in the human history has been Isaac Newton. He has been also one of the most important due to, among some other important studies, his three laws.

They will not be stated in an academic way in the beginning, just because they are usually stated in a very difficult way to understand language, this lesson will begin by explaining them in an easy way and, after that, their complexity will be shown.

In fact these three laws are known by all of us although we do not know it. For example the first law states that if you do not apply a force on anything or the forces applied compensate each other, that anything will not move or will not change its speed if it is moving. All of us know perfectly this is what really happens, if you do not touch anything, that anything will not move, and we can even think this law does not need to be stated.

But if we think a little bit more about it, we will find is a very important law for designing anything we do not want to move, for example a building. If we look above us we will see the ceiling, and for sure it is not moving, and there is a reason why. If we see it from the first law point of view, the ceiling is not falling because there is a force that compensates its weight, that force it is made by the beams above us, and the bigger the weight, the bigger have to be the beams, and the size of the beam can be calculated. So, Newton’s first law has suddenly become an important tool for designing buildings, bridges, towers, structures...

Exactly the same happens with the second law, which could be stated in an informal way saying that if you apply a force to a body it will move. And, once again, it seems to be simple and intuitive but it is not, because the bigger the force the faster will be the movement, and the bigger the body the slower will be the movement. Thus we can design movements taking in account these factors, you can work out the force you have to apply to make a body move in the way you want to. For example the acceleration you want a vehicle to have has to do with the power of the engine and the mass of the vehicle, and you have to apply the second Newton’s law to obtain the acceleration you want.