Prabin Kalikote

We know that mercury is only the metal that exists in the state of liquid with a freezing point - 39C and boiling point 357C. The range of its FP and BP is suitable for measuring normal temp. It is also a good conductor of heat. It has a low specific heat capacity i.e.140 J/KgC. So, it is used as a thermometric liquid.

We know that in the desert the land is covered all by sand. Sand has low specific heat capacity which means it gains and loses heat very fast. So, during the day it gains max heat and becomes hotter and during the night it loses all the heat and becomes very cold.

We all know that, the temperature of our body higher in the bedroom than the temp. of surrounding. So, when we go outside, our body loses the heat and we feel cold.

After strolling outside in open air the temp of our body again decreases below the temp. of bedroom. So, when we come back to the bedroom, our body gains heat and we feel warm.

We know that the density of solid ghee is more than that of liquid or hot ghee. So while freezing, all the frozen ghee starts to displace to the bottom. But, water has a higher density at 4⁰C than at 0⁰C. It means water has a higher density than ice. So, while freezing, ice displaces to the top.

As we all know that water has the highest specific heat capacity. It means that it has the highest capacity of absorbing heat. So, the heated water releases heat for the longest time. As the hot bottles are used for heating purposes, hot water is used in them.

We know from the principle of calorimetry that the heat gained by a cool body from a hot body is equal to the heat lost by a hot body. To cool the engines, something should absorb its heat and water has the highest capacity to absorb heat as its specific heat capacity 4200 J/Kg⁰C.
So, water is used to cool the engines of machines.

Calorimetry is the measurement of heat lost or gained by an object.

The principle of calorimetry state that 'When a hot body is mixed with a cold body, the heat lost by the hot body is equal to the heat gained by the cold body, provided that no heat escapes to the surroundings.'

Therefore,  Heat lost = Heat gained.