I have two transparent bottles of nearly the same base diameter and cap diameter (Implying that both bottles have similar cap and base area respectively). But one is taller than the other by 15 cm.
The bottles are made of the same material (PolyPet) and I poured cold water at the same temperature to both of them and observed.
I found that :
If I opened the cap the temperature of water just around the cap was higher than that of water below it. The water below it had a comparably low temperature.Does that mean that waters acts as an insulator to prevent heat exchange (to some degree)?
The smaller bottle cooled down later while the taller one faster. I thought that the reverse would happen as it would be relatively easy to cool down a smaller quantity of liquid than a larger one. But the opposite happened.
I could not find any reasons for the above. I repeated the above steps thrice getting the same results.