Question

15.
5. Indian style of cooling drinking water is to keep it in a
pitcher having porous walls. Water comes to the outer
surface very slowly and evaporates. Most of the energy
needed for evaporation is taken from the water itself
and the water is cooled down. Assume that a pitcher
contains 10 kg of water and 0:2 g of water comes out
per second. Assuming no backward heat transfer from
the atmosphere to the water, calculate the time in
which the temperature decreases by 5°C. Specific heat
capacity of water = 4200 J kg -1°c-i and latent heat of
vaporization of water = 2:27 x 10 J kg ?
16.
-3​

Answer 1

Answer:

Yes, heat is a conserved quantity. Suppose two bodies A and B are at different temperatures, wherein A is higher and B is lower. When they are brought in contact, the heat given by A is equal to the heat gained by B. Thus, the heat is conserved in the system.

Here, we have ignored the heat exchanged with the surroundings. If we consider the surroundings, the heat of the system will be conserved.