Answer:
They can't hear an echo in small room because in it the sound can't be reflected back. For an echo of a sound to be heard,the minimum distance between the source of sound and the walls of the room should be 17.2 m.
hopw it helps
Answer:
160 m
Explanation:
The intensity, I, of the sound is inversely proportional to the square of the distance, r, from the source.

Hence,


From the question,
is half of 



The various contributions involved till the chapati is made is given below.
<h3>What is food?</h3>
The substance that we intake for the body to charge up by giving nutrients is called the food.
Wheat is a staple food. We make chapati from flour obtained from the wheat grains.
The various contributions involved till the chapati is made is given below.
Take required amount of atta in a container
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Add water accordingly to form a dough
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Apply oil to make dough smooth for long time
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Take small dough, make it a ball shaped and apply dry flour
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Roll it using rolling pin on the chapati maker plate
↓
After making it circular or any shape you want, place it on hot tawa
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Bake it on both the sides
↓
Chapati is ready
Thus, the flow chart is made.
Learn more about food.
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warm fluids are less dense than cold fluids