Question

Why sitting on a drawing pin can be painful

Answer 1

Drawing pins are sharp and pointed and have less area in contact. So if area in contact is less the pressure will be more. And pressure is inversely proportional to area of cross section. So more pressure is acting on us and it can be painful

Answer 2

it can be painful because surface area is proportionate to pressure of surface area is less then the pressure will be greater and vice versa