Advertisements
Advertisements
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?
Advertisements
उत्तर
When the hands are placed at some distance from the mouth and the air is blown again, this time the air from the mouth does not feel much warmer. This is because, due to the distance from the mouth, the air gets mixed up with outside air and thus becomes cooler.
APPEARS IN
संबंधित प्रश्न
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?
Have you ever burnt your tongue when you ate or drank something that was too hot? How do you cool some food when it is too hot?
If you were to cool these three hot things – dal, roti, rice – in which ways would you do so?
Make whistles of the things given below. Write in a sequence–from the loudest to the softest whistle.
– Wrapper of a toffee
– A leaf
– A balloon
– The cap of a pen
– Any other thing
Can you name some things which produce melodious or pleasing sounds when we blow into them?
Count how many times in one minute do you breathe in and breathe out.
Now again count how many times in one minute you breathed in and out.
We blow to cool hot things as well as to warm them. Give examples of each.
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?
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?
