My professor's question



Professor PVS Rao, who was my guide during my master's degree work, sent me a question. 

I answered it correctly and he gave me 99% marks for it. I thought that kids nowadays think very well and might be able to answer the question. To make it easier for you, I am giving a few clues. 

The question is: 

"I have two thermos flasks at home in my flat. 

I wish to QUANTITATIVELY AND ACCURATELY compare how good they are, without moving out of my house. 

HOW? 

I have no equipment". 

Clues: 
1) Do you have ice cubes at home? 

2) If a cube of ice is in a good flask, will it melt faster? Or slower? 

3) What is a flask expected to do? Keep cool things cool, or to heat them up? 

Think this out, and discuss it with your parents or others in the house. 

Srinivasan Ramani  

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