Stress and Pressure

Well...

We all came across these two words, stress and pressure. But, it would have been always confusing to differentiate each of them individually.

Here I will help you to come out of this worry and will give an overall idea about those two terms.....

First of all, what is stress???

Load / Area....! Isn't it...???

Come on dears....never ever say this...it is a formula for stress and it doesn't define the word stress in anyways.

Then, what is stress...?????

As you read in a standard author book, stress is an internal resistance offered by the body against the external force acting on it.

Ohh...!! What it does mean???

Wait.... What they are saying is that, stress is a resisting force, that is, stress is an induced force due to the deformation(strain) caused by the external load....

Still not clear, right....

Stress will never be created without any deformation caused due to the applied load. So stress is a dependent property which causes due to the strain (independent property).

Clear...????

Okay...then, what is pressure???

Generally, pressure is a normal load applied on an object or a substance.

Need to be elaborated....let us take a four legged chair as shown below...

Consider the area which resists the load of the person sitting on it is 1 square meter (say).

Let us have two cases here.....one person weighs 500 N, that is approximately 50 kg is sitting on it. then the pressure exerted by him on the chair area is 500 N/Sq.meter.

The second person weighs 300 N, that is 30 kg (appx.). Then the pressure exerted will be 300 N / Sq.meter.

In this case, the resisting area is same but the load varies person to person according to their weights. So the pressure varies respectively.

As both the magnitudes are measured per unit area, they have the same units representing load per area.

Hope you got it...comment if you still not clear or if any mistakes you found in the content...I am pleased to correct it....