NCERT Book Class 6 Science Chapter 11 Air Around Us

11 Air Around us

W
e have learnt in Chapter 6 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
Fig. 11.2 Making a simple firki
many ways. You notice it when the
leaves of the trees rustle or the clothes Move it a little, back and
hanging on a clothes-line sway. Pages forth. Observe, what happens.
of an open book begin fluttering Does the firki rotate? What makes a firki
when the fan is switched on. The moving rotate — moving air, isn’t it?
air makes it possible for you to fly your Have you seen a weather cock
kite. Do you remember Activity 3 in (Fig. 11.3)? It shows the direction in
Chapter 3 in which you separated the which the air is moving at that place.
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
(Fig. 11.1)?
Fig. 11.3 A weather cock

11.1 IS AIR PRESENT EVERYWHERE
AROUND US?
Close your fist — what do you have in
it? Nothing? Try the following activity
Fig. 11.1 Different types of firki to find out.
Activity 1 Activity 2
Let us make a firki of our own, following Take an empty open bottle. Is it really
the instructions shown in Fig. 11.2. empty or does it have something inside?
Hold the stick of the firki and place it Turn it, upside down. Is something
in different directions in an open area. inside it, now?