We know that it takes longer to boil some water than to warm it. Also boiling water takes longer to cool down than lukewarm water does. So for the rise and fall of different amounts of temperature, different amounts of heat are absorbed or released.
Again, increasing the amount of water to be boiled, increases the time taken to boil it too. From this, we can conclude that the amounts of heat absorbed or released by the bodies of the same material but different masses for a fixed rise or fall in temperature depend on their masses.
Factors that Affect Heat Transfer:
From the above observations, it can be inferred that the amount of heat absorbed or released by a body depends on:
i. The change of temperature of the body.
ii. Mass of the body.
iii. Material of the body.
1. Temperature:
Amount of heat gained or lost by a body of fixed mass is directly proportional to the rise or fall in its temperature.
2. Mass:
Amount of heat gained or lost by a body, for a fixed rise or fall in temperature is directly proportional to its mass.
3. Material:
Heat gained or lost by a body depends on its materials.
When a body of mass m receives heat H, the rise in temperature is t.
H ∝ mt
or H = smt …equ(1)
Where s is a constant whose value depends on the material of the body.
It is to be noted that t in equ(1) isn’t the actual temperature but the change in temperature of the body. So only the heat gained or lost can be measured by this equation. It is not possible to measure the total amount of heat contained in a particular body.