The pressure

I think this topic is some easy. Since we were kids at school they taught us some notions about pressure. Today I will talk about a known mathematical
equation that will help us to understand better these expressions, at the same time, to learn about the pressure in its maximum simple splendor.

When the applied force is normal and uniform distributed over a surface, we can speak of a pressure that relates a force acting on the surface.

Its simple mathematical expression indicates two relations one proportional and another inversely proportional. You must look at the image below (equation) for the next. First, the pressure is proportional to the force, that is, if the force increases, the pressure will also increase. Second, the pressure is inversely proportional to the area, in this case if the area decreases, the pressure will increase.

Thanks to the above we can now understand some phenomena about pressure. For example, have you ever seen winter snow boots? If you know it, you will understand why winter boots are bigger than normal. This is because our weight represents the force caused by gravity, and the surface where we stand is the area. As the area is inversely proportional to the pressure, while the area increases the pressure decreases that means we do not sink in the snow. Sometimes people use a racket in their boots to increase the area.

Why does not a blow go through our skin? Why does a needle do it? The answer is in the area. The force is important but in this case the area predominates because in a needle it is smaller than a fist, therefore the pressure is greater and the needle manages to pierce the skin.

Easy, right?