Pressure Exerted by Liquids
We know that all liquids have weight
Example-Water has weight
When this liquid gets filled inside a container,it exerts pressure because of weight of liquid
Example 1 Attaching Balloon to Test Tube
Suppose we attach balloon with test tube
We will fill the test tube with some water
It makes the balloon bulge a little
We put some more water in test tube
It makes the balloon bulge even more
This shows that water exerts pressure on balloon(more the water,more pressure is exerted on balloon
Example 2 Hole in Water Bottle
We know that water flows through water Bottle
if there is hole in water Bottle,water comes out very fast like a fountain
This shows that water exert pressure on bottle.
Gases Exerting Pressure
We know that there are many gases like Nitrogen, Oxygen, Carbon Dioxide in the atmosphere
When these gases come in contact with a substance, there is collision of molecules of gas with molecules of substance
This causes air pressure
Example 1 - Inflating a balloon
When we inflate balloon,air comes inside the balloon because of pressure exerted by molecules of air on the balloon Due to this balloon inflates
We have to close its mouth
If we do not close its mouth,air escapes out
This shows air has pressure
Example 2 - Filling air in bicycle tyre
When air is filled into bicycle tyre by using a pump,the tyre tube gets hard because of pressure exerted by molecules of air on tyre tube of bicycle
If bicycle tyre gets punctured,air escapes very fast
This shows air has pressure
