NCERT Solutions for Class 5 Environmental Studies Chapter 13 - Blow Hot, Blow Cold

Question 1:

In the winter when we feel cold, then why some times we blow on our hands ?

Answer:

We feel warm on blowing on our hands in winter, because the air coming from our mouth is warmer than the air around us.

Question 2:

Why Balishtiye was surprised to see that woodcutter was blowing to warm up hands and now he is blowing to cool the hot potatoes ?

Answer:

Balishtiye was surprised to see that woodcutter was blowing to warm his hands in the morning and now he is blowing to cool the hot potatoes. How could same blow from mouth can warm the hands and cool the hot potatoes ?, he was surprised.

Question 3:

Sonu was feeling very cold. Why he was blowing his hand again and again ?

Answer:

Sonu was blowing on his hands to feel warmth, because warm air of the mouth gives warmth to his hands and he get relief from the cold.

Question 4:

From which things you can make whistle ?

Answer:

We can make whistle from wrapper of a toffee, a leaf, a balloon, the cap of a pen etc.

Question 5:

The air coming from your mouth is warmer or cooler than the outer temperature ?

Answer:

The air coming from our mouth is warmer than the outer temperature.

Question 6:

Why water vapours appear in the mirror when we blow on it ?

Answer:

When we blow on a mirror then hot air strikes the mirror. The steam cools down into water vapours.

Question 7:

What difference in the measurement of our chest takes place when we jump ?

Answer:

When we jump our breathing process fastens, due to which our chest moves up and down, and measurement of our chest changes.

Question 8:

What is the difference in counting the breath on jumping and sitting ?

Answer:

The counting of our breath becomes less on sitting quietly. When we jump then our breath becomes fast. So, the counting of breath increases on jumping.