Question

Why do you think it is necessary to define as separate quantity called pressure why is defining only force not enough

Answer 1

pressure and force are likely terms they have different properties

Answer 2

Pressure =Force /Area
Force on unit area is called Pressure..
So pressure depends on area..
Therefore two bodies applying same force can apply different pressure...
Without pressure you can never know whether
it is convenient to use a blunt knife or a sharp knife though both can apply same force...
Blunt knife offers a greater surface area than a sharp knife ..
So it is difficult to cut something with a blunt knife ...
It is easier to cut with a sharp knife as it offers smaller surface area.....
Inference :
Both knives can apply equal forces , but we found that the knife with small surface area (sharp one) was more convenient....
Pressure increases with decrease in surface area...
Therefore we need an entity called Pressure to ease our understanding of things...

Hope you understood...

Happy to help....