N°5 – Quantities calculation of sensible heat training (A level)

Quantities calculation of sensible heat is he application of heat can cause a variation in temperature or a change of physical state, such as the transition from a solid to a liquid state.

• When heat applied to or removed from a type of matter only leads to a variation of temperature, without changing its physical state, we talk about sensible heat.
• When heat applied or removed leads to a change of physical state without a variation of temperature, we talk about latent heat.
• When heat applied or removed leads to a change of physical state and a variation of temperature, we talk about total heat.

 
We are going to learn how to calculate quantities of sensible heat.
 
If we know the specific heat of a body we know how much heat needs to be applied to raise 1 [kg] by 1 [K]

If we are working with several [kg], we just need to multiply by the number of [kg], and if the temperature is raised by several [K], we just multiply by the number of [K].

Q = M x C x ΔT
With:
Q: Quantity of heat in [kJ]
M: Masse treated in [kg]
C: Specific heat in [kJ/kg.K]
ΔT: difference in temperature increase [°C] or [K])

Note: « Δ » is an ancient Greek letter (pronounced delta) which means « difference of ».
« ΔT » is therefore the difference in temperature which can also be written as DT.
Hence: Q = M × C× ΔT = M × C× DT