Relax, settle down.
What is the meaning of Pseudo?
Which is not real. Do you know the meaning of Law?
Is there any other Law that you know of? There is only type of Law, according to me. What is the
meaning of Law?
Justice which has a long arm.
It is blindfolded.
That is not necessary it depends on the country, in our country it is blindfolded. But my meaning of
law is something which is applicable to all, something which is universally applicable. The general
meaning of the word law is it is something that is valid over everyone equally, which is not at all like
that here. It is different for the common man and different for politicians.
So when we say Newton’s Law of Motion, so effectively when the word ‘law ‘ is used a special
condition is assigned to that that it should be applicable in all scenarios which does not happen in
real life. So ideally speaking Newton’s Laws are not true or completely laws which you can apply in
all situations. Better to say then Newton’s Definition of or Newton’s three different statements.
Newton was a very famous person, he had a lot of respect and value, he was a famous scientist and
because of that respect we still call it Newton’s Law. You can challenge the validity, people have
done it earlier so you don’t have to take that tension.
Newton’s Laws of Motion are not valid in a non inertial frame of reference, okay. So first let’s take a
look at what is frame of reference.
The Pseudo Force that we are going to study about, to find out about pseudo force there are a few
small steps in between that we have to look at. So first we take a look at frame of reference.
Anything which is taken as a reference, anything which is taken as a reference to discuss motion of
an object is called frame of reference. If there is any object that you are considering as reference to
discuss the motion of an object, that will be considered as frame of reference. It can be a car, it can
be a jeep, it can be you yourself, or it could be a point, anything can be taken as a reference. If you
are explaining about the motion of an object that is with respect to you or according to you, as a
frame of reference. If I am in a moving car, and if I am explaining about the motion of an object
while I am in the moving car so that will become, the car will become my frame of reference. So
anything which is used to discuss the motion of any object will be known as the frame of reference,
We have divided frame of references into two broad categories. One is Inertial Frame and the
second is Non-inertial Frame of Reference. We will see them one by one.
Inertial Frame of Reference – there is no real inertial frame that exists in the world.
Next point, under Newtonian physics we have considered ‘earth’ as inertial frame. That means in
Newtonian physics or phenomena of physics in day to day life we have considered earth as an
inertial frame. So now with respect to earth we will define which frame we can call as inertial and
which frame we can call as non-inertial, okay.
So write the definition of Inertial Frame, any frame of reference, any frame of reference which is at
rest, any frame of reference which is at rest or moving with constant velocity, moving with constant
velocity, constant velocity with respect to earth, with respect to earth will be taken as, will be taken
as inertial frame of reference, will be taken as inertial frame of reference. On the other hand,
anything which is accelerating with respect to earth.
Newtons Law of Motion & Friction – Pseudo forces