# Why does sword and knife has a sharp edge and a sharp tip

I was curious why the edge of knives is kept sharp. So I tried to uncover the answer to this question and In this article, I will share the answer with you. The simple answer is to minimize the area to make more pressure but there is more in it. Friction plays a crucial role in the working of this phenomenon.

The formula of pressure is,

P=F/A

where F denotes force applied on given surface area A.

The sharp edge of knives, blades, etc., are provided to cut things easily. Smaller the area of these cutting edge tools gets they are more likely to apply force on a smaller area of them.

## Why friction plays a crucial role for sharp edges of knives and blades

It is so because knife as a simple machine works on the principles of friction which says friction is high between rough surfaces and how much the surfaces in contact are pressed together so when the knife is sharpened to have a sharp edge the surface becomes rough and reduces the surface area so that they are pressed very hard in which case the pressure increases with a small force applied to it.

Same applies to a needle.

## Ending of Interstellar

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