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प्रश्न
Take a glass. Bring it near your mouth and blow hard on it. Do this two or three times. Does the glass look hazy?
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उत्तर
Yes, a mirror can also be made hazy in the same way. On blowing air from the mouth on the mirror, the mirror becomes moist. The air blown from the mouth is hot and the mirror is cold. The hot air that we breathe out contains water vapours which turn into tiny droplets of water when it comes in contact with the colder mirror. This makes the mirror moist and hazy. The air blown from the mouth is wet.
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संबंधित प्रश्न
Miya Balishtiye was confused when he saw the woodcutter blowing on his cold hands to make them warm and on the hot potatoes to cool them.
- Now put your hands at some distance from your mouth, and blow again. Does the air from your mouth feel warm? Why?
Can you think of any other way in which you use the warmth from your breath?
Balishtiye saw that the woodcutter was trying to cool the hot potatoes by blowing on them. What would have happened if he had eaten the potatoes without cooling them?
If you were to cool these three hot things – dal, roti, rice – in which ways would you do so?
For what other things do you blow air from your mouth?
Picture 1 - Mini tried to cool her tea by blowing on it. Which do you think will be hotter – Mini’s tea or the air she blew from her mouth?

Have you seen people playing different musical instruments like flute, dholak, been ...., guitar, mridang, etc. Can you recognize their sounds with your eyes closed? Find out more about these musical instruments. Collect their pictures too.
Can you make a mirror hazy in the same way? Can you tell by touching the mirror what made it hazy? Is the air you blew from your mouth dry or wet?
Measure your chest
– Take a deep breath in
– Ask your friend to measure your chest with a thread. Measurement ____________
– Now breathe out. Again ask your friend to measure your chest. Measurement ____________
– Was there any difference in the two measurements of your chest?
You have all heard the ‘tick tick’ of the clock. Have you seen a doctor using a stethoscope to listen to our chest? What do you think she hears? Where is the sound coming from? Is there a clock inside your chest that keeps ticking away?
