Question

why a sharp needle pierces the the wood easily but not a blunt knife although the force applied on both the needles is same

Answer 1

As pressure is inversely proportional to area so in case of needle area is less so presurre is more but in case of blunt knife area is more so pressure is reduced hence a sharp needle pierces the wood easily than a blunt knife.

Answer 2

Hello!

Here is your answer

A sharp needle pierces the wood easily than the blunt one as the sharp knife has a smaller area and a greater pressure.
When pierced, the wood gets a greater pressure of the sharp knife than the blunt one as it has a greater area and smaller pressure.

So there's a rule of remembering Pressure concept.

Greater area - Smaller Pressure

Smaller area - Greater pressure.



Hope it helps!