Question

Why the cutting edge of a knife should be as sharp as possible?

Answer 1

We use knifes to cut Something. Pressure plays an important role here.

We know that LESS THE CONTACT SURFACE MORE THE PRESSURE WILL BE.

The contact surface of the knife is very small when it is very sharp.

So the cutting edges of knife should be sharp.

:)

Answer 2

Cutting edge of a knife should be as sharp as possible
This is because when  the area of the knife decreases , pressure .

Pressure = Thrust/Area

Pressure is inversely proportional to area.

This means that when area increases pressure decreases.
Also , when area decreases , pressure increases