Force and Pressure

 Force!

                                                                We hear the usage of this term many times in our day to day life.

We might not know that we're using it.

Opening a door, riding a bicycle,

lifting an object are few of the most common things

that we perform in our daily lives,

and all these require a force.

What is a force?

Consider a ball lying on the ground at rest. It's not moving.

Suppose this player here wants to pass this ball to his teammate,

who is standing on the other side of the pitch.

How will he do that?

He needs to make this ball move in the direction of his teammate.

So he will kick the ball in the direction of his teammate.

When he kicks the ball we say that he applied a force on the football.

Yes, the kick is nothing, but the force he applied on the ball.

Now suppose that we have a desk here at point "A".

A person wants to move this desk from point "A" to this point "B".

Again, how will he do that?

Here he will push the desk towards point "B".

In this case we say that the person applied a force on the desk

in order to shift it.

The push here, is the force that the person applied on the desk.

Similarly when you lift some object from the table

we say that you applied a force on that object.

Here the force is applied in the form of lifting.

So, forces are nothing but actions such as kicking,

pushing, lifting etc. performed on objects.

There are many such actions that we can perform.

We have already seen few of these.

Some more of them are given below.

While riding a bicycle, we pedal it continuously to keep it in motion.

Here pedaling is the force that we apply on a bicycle.

Hitting the hammer on a nail is also a force applied on the nail.

What about stopping a moving ball?

Yes, even stopping the ball means we're applying a force on it.

We applied some force, to stop the ball.

Opening a drawer, plucking the string of a guitar,

moving a piece on a chessboard

are some of the other actions performed on objects.

So performing these actions on objects,

is nothing but applying force on them.

But these are just a handful of simply too many actions

that we can perform on the objects.

And it's not possible to write each one of those.

But we can categorize all these actions into two basic ones.

That is we can describe all these actions under two actions namely

"pushing" and "pulling".

For example when we open this drawer

we are simply pulling the knob of the drawer to open it.

Similarly, when we are drawing or lifting a bucket of water from the well,

We are pulling the bucket towards us.

What are the actions that can be described under pushing?

Actions such as passing the ball,

hitting the hammer on the nails etc. can be thought of as pushing an object.

Are there any actions that can be described under both?

Yes, there are !

Suppose there is a book on the table,

you can either pull it towards you like this

or push it away from you like this.

So moving an object can be described under both.

Similarly opening or shutting a door can be thought of as both.

So we can safely say at this point

that the forces are nothing, but the push or pull applied on objects.

Forces are due to interaction between the bodies or objects.

What does it mean?

Let's go back to our first example of this video.

Here, in order to pass the ball to his teammate,

the player must move it.

That is he must interact with the ball

to move it in the direction of his teammate.

He interacts with the ball by kicking it.

The ball and the player interact with each other.

In the second example in order to move the desk from point 'A' to point 'B',

he must interact with the desk.