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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?
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.
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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.
- Have you warmed your hands in winter by blowing on them when they are cold? How does it feel?
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?
Have you seen someone blowing on their spectacles to wipe them clean? How does the air from the mouth help in cleaning the spectacles?
Take a glass. Bring it near your mouth and blow hard on it. Do this two or three times. Does the glass look hazy?
Put your hand on your chest. When you breathe in, does your chest come out or go in.
Put your finger under your nose. Can you feel any air when you breathe out from your nose?
While playing, Amit hit a wall. His forehead was swollen. Didi immediately folded a scarf (4-5 times), blew on it, and kept it on Amit's forehead. Why do you think didi did this?
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?
Do you want to listen to your heartbeat? Take a rubber tube as long as the distance from your shoulder to your elbow. At one end of the tube fix a funnel. Place the funnel on the left side of your chest. Put the other end of the tube to your ear. Listen carefully. Did you hear a dhak dhak sound?
Can you understand from the movement of the snake - if the air is moving upwards or downwards?