A Wooden block kept on a table exerts a force on it,
and we know that the wooden block is a solid substance.
What about liquids?
We know that liquids are kept in containers.
Do liquids or fluids exert pressure?
Yes, they do.
They exert pressure on the base and the walls of the container
in which they are enclosed.
The pressure on the base will be downwards
and on the walls the pressure will be sidewards.
We can also derive something interesting
if we look at the fluid in terms of layers.
Say there's water kept in a plastic container.
Let's divide the fluid into five equal parts.
You can see that the second layer of water
is holding the weight of the first layer.
Similarly the third layer is holding the weight of the first
as well as the second layer.
And the fourth layer is holding the weight of the top three layers
and so on and so forth.
So clearly, the pressure at the bottom most layer is the maximum.
There's even a way you can find this out.
Near the topmost layer make a little hole at the side.
You'll see that the water flows out from that hole like this.
It doesn't roll along the walls, it flows out at an angle.
Now let's make a second hole near the layer under it.
You'll see that the water flows out at a wider angle
as compared to the earlier case.
We continue to make holes in the wall,
and we'll notice that the water literally squirts out.
This proves that the pressure at the bottom
is much more than the pressure at the topmost layer.
What about the upward force exerted by a liquid?
How do we understand that?
We will see that in our next video.
