Question

Why do tools meant for cutting always have sharp edges?

Answer 1

Thank you for the question!
Sharpe tools are best for for cutting. This is because force acts perpendicularly  per unit area. According to the formula P=F\A  force is directly proportional to the pressure. When the tool will be sharp it means that the  surface area reduces thus, in this way more force can be applied on an object and it can be cut easily and quickly. So cutting tools always have sharp edges not blunt edges.
Hope it helps.

Answer 2

cutting need a Sharp tools so that the exert large pressure as the area is contacted is small this is the reason why a knife for sharp edges

pressure and area are inerertionly proportion to each other the more area, less will be the pressure and the smaller area, large will be the pressure