Air Around Us-Introduction

Air Around Us-Introduction

Introduction                        
We have learnt that all living things require air. But, have you ever seen air? You might not have seen air, but, surely you must have felt its presence in so many ways.You notice it when the leaves of the trees rustle or the clothes hanging on a clothes line sway. Pages of an open book begin fluttering when the fan is switched on. The moving air makes it possible for you to fly your kite. Do you remember Activity in
which you separated the sand and sawdust by winnowing?
        Winnowing is more effective in moving air. You may have noticed that during storms the wind blows at a very high speed. It may even uproot trees and
blow off the rooftops. Have you ever played with a firki?


Move it a little, back and forth. Observe, what happens. Does the firki rotate? What makes a firki rotate — moving air, isn’t it?
Have you seen a weather cock ? It shows the direction in which the air is moving at that place.