Stefan Boltzmann Calculator, Formula With Example

Stefan Boltzmann Calculator :

This Stefan Boltzmann law calculator describes the Area in meter square(m²), Temperature in °C, Radiated power in watts(W), and you get the calculator check it.

Stefan Boltzmann Law Calculator

Stefan Boltzmann Formula :

Stefan Boltzmann formula is thermal radiation ΔQ(j) in joule and time Δ t(s) in second is equal to the emissivity ε(w/cm2) in watts per centimeter2  and multiply the Stefan constant value σ(w/m2k2) in watts per meter2 per kelvin2 and multiply the surface of the system A(m2) in meter2 and multiply the temperature T4(0c)  in degree celsius. Hence the thermal radiation of the Stefan Boltzmann formula can be written as,

ΔQ(j)/Δ t(s)(w/cm2)(w/m2k2)*A(m2)* T4(0c)

Where,

σ →5.67*10-8 W/m2 K4

A→ surface are of system

ε → emissivity in w/cm2

σ→ constant in W/m2 K4

net rate of radiation ΔQ/Δ t=ε*σ*A(T41 – T42)

Example:1

Calculate the net radiation rate, Let A=1.6m2? In a person  cools by radiation. Suppose a person stands in a room with dark walls at a temperature of 180  If εstin=0.71 and temperature of skin is 360c.

Answer:

ΔQ/Δ t=ε*σ*A(T41 – T42)

=(1.6)(0.71)(5.67*10-8)(36+273)4-(18-273)4

=717 J/s

Example:2

A person  cools by radiation. Suppose a person stands in a room with dark walls at a temperature of 200  If εstin=0.81 and temperature of skin is 4 60c ?

Answer:

ΔQ/Δ t=ε*σ*A(T41 – T42)

=(2.6)(0.81)(5.67*10-8)(46+273)4-(20 +273)4

=7370 J/s

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