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heat and all the formula
Answers
Answer:
Heat transfer is defined as the process of transfer of heat from a body at higher temperature to another body at a lower temperature. Heat, as we know, is the measure of kinetic energy possessed by the particles in a given system. When the temperature of a system is increased, the kinetic energy possessed by particles in the system increases. When this system is brought in contact with another system whose temperature is lesser as compared to the first, the energy gets transferred from the particles in the first system to that in the second system.
Heat transferred from one system to another is given by the following equation,
Q=m×c×ΔT
Here, Q is the heat supplied to the system, m is the mass of the system, c is the specific heat capacity of the system and ΔT is the change in temperature of the system.
The transfer of heat occurs through three different processes, which are mentioned below.
Conduction
Convection
Radiation.
Conduction:
Heat transferred by the process of conduction can be expressed by the following equation,
Q=kA(THot−TCold)td
Convection:
Heat transferred by the process of convection can be expressed by the following equation,
Q=HcA(THot−TCold)
Here, Hc is the heat transfer coefficient.
Radiation:
The Heat transferred by the process of radiation can be given by the following expression,
Q=σ(THot4−TCold4)A
Here σ is known as Stefan Boltzmann Constant.
Derivation:
From the definition of specific heat capacity, we can say that, it is the total amount of heat that is to be supplied to a unit mass of the system, so as to increase its temperature by 1 degree Celsius.
Let us consider a system of mass ‘m’. In order to calculate the relation between the rise in temperature with the amount of heat supplied, we multiply the specific heat of the system by the mass of the system and the desired rise in temperature.
Now, the total heat to be supplied to the system can be given as,
Q=m×c×ΔT
Real Life Example: Let us consider a pitcher of water that is to be heated till its temperature rises from the room temperature to 100 degree Celsius. In this case, as we know the mass of the water and its specific heat capacity at the given conditions, we can use the above mentioned formula to calculate the amount of heat to be supplied.
Explanation: