Question

why is it difficult to cut an apple with a blunt knife

Answer 1

it is because the area decreases and pressure will increases as the area is proportional to pressure..... and one more thing is that.. the area of contact in a blunt knife is more so it decreases the pressure applied but the area of contact in sharp knife is less so the pressure is more so it is easier to cut.

Answer 2

suface area is more and pressure is less