Imagine you're sitting on a recliner chair
watching your favourite movie on a lazy Sunday.
And your mom calls out your name
and asks you to run some errands.
You can imagine
how difficult it would be for you to get up and do the work.
Imagine you're practising for your 100 meters race on this track .
And somebody asks you to stop immediately within a second.
Will you be able to do it?
What if you're suddenly ask to turn towards the right?
Will you be able to turn immediately?
The answer to both the questions would be a NO.
You can stop yes, but gradually. You can also turn
but not sharply.
And guess what it's the same story with every object.
Every object will continue to do what it's doing .
If it's at rest it will remain at rest
and if it's in motion it will stay in motion.
But what can change this?
Yes only an unbalanced force can change this.
If it's at rest and an unbalanced force acts on it
it will move.
If it's in constant motion and an unbalanced force acts on it
it may accelerate or change direction.
And this is nothing but the Newton's first law of motion.
Here's the correct definition.
An object at rest stays at rest and an object in motion stays in motion
with the same speed and the same direction unless
unless acted upon by an unbalanced Force.
In simple words, it means that the objects continue to do what they're doing
unless some external unbalanced force acts on them.
We can also understand this using a simple diagram.
If the Forces are balanced there can be two cases.
An object may be at rest or an object will be in motion
at a non zero constant velocity in a particular direction.
These can be the only two cases when the forces are balanced.
In the first case the object will continue to remain at rest.
And In the second, the object will continue to stay in motion
at the same velocity and in the same direction.
Don't forget, these two cases will remain true,
only if the forces are balanced..
In the next video we will look at a few applications of the first law of motion.
