# How Do You Define Pressure In Physics?

Pressure is defined as force acting per unit area.

Pressure = force / area

The SI unit of pressure is Newton per metre squared or pascal.

To illustrate the difference between pressure and force, consider two identical bricks of equal weight. One brick stands on its side and the other on its end. Both bricks exert the same force on the ground but the upright brick exerts greater pressure against the ground due to its smaller area of contact.

It is much easier to cut fruit with a sharp than with a blunt one. In the case of a sharp knife the blade makes such a small area of contact with the fruit that the pressure below it is very high and easily cuts the fruit.

The pin used on a drawing board has a broad head and a pointed tip. When force is applied on the head, the pressure exerted on the tip, due to its small area, is so large that it pierces the board.

Broad wooden sleepers are placed below the rails to reduce the pressure exerted by the weight of the train.
thanked the writer.
Anonymous commented
Thankyou very much, I just stumbled upon this and although studying pressure for a semester at university, you have just claified a lot of what I didn't understand about pressure :)