Normal Force/Reaction (Laws of motion)

Hello Friends, Today you will learn what is normal force and how it is used in physics in chapter 5 of your physics ncert book. ok

NORMAL FORCE(no inclination):-
It is an opposing force that comes into play when two bodies are in contact.

let is understand with this illustration

fig-(i)

In fig(i) you can see that two bodies are in contact and suppose the system is in equilibrium (i.e no external force is acting on bodies). 

here Body a will exert Force F on body b because it have mass and acceleration due to gravity is acting on it.

now F=ma, here a=g therefore, Box a will exerts (mg) force on body b. 

We know that , according to newton' third law of motion:- 

for every action there is equal and opposite reaction. 

So if box A exerts force on box B (as action) then box B will exert equal but opposite force (as reaction).

and this opposite force is known as Normal Force or Normal Reaction in physics.

Now you knows what is normal force.....!!!

Uses of normal force in physics 

Normal force is a very simple but important part of physics, it is used to solve problems based on fbd (Free body diagram) to know how much normal force does a body giving.. and various probem solution is given by this simple term . it cannot solve whole problem at it's own but without it the problem cannot be solved 

OK

Watch this simple Video to understand more about it...............

Source:- Knowledge from books (S.L Arora)

By:- DG Kumar