Question

Why a sharp knife is more effective than a blunt knife?

Answer 1

1. A sharp knife has a very thin edge compared to a blunt knife.
2. we have $Pressure=\frac{Force}{Area}$
3. A sharp knife cut objects better because due to its very thin edge, the force of our hand falls over a small area of the object producing a large pressure and this pressure cuts the objects easily.
4. On the other hand, a blunt knife does not cut an object easily because due to its thicker edge, the force of our hand falls over a large area of the object and produces lesser pressure. Thus lesser pressure cuts the object with difficulty.