What Equations Calculate Thermal Radiation and Wavelength Peak Intensity?

The object's temperature is not given, so you cannot find its peak wavelength. You also need to know the object's emissivity and surface area to find the power emitted per square meter. In summary, the conversation discusses an object that emits thermal radiation and the equations needed to calculate its power and peak wavelength. However, more information is needed, such as the object's temperature, emissivity, and surface area.
  • #1
Gh0stman
1
0

Homework Statement



Consider a 5.50×10 (to the 4th power) object that emits thermal radiation.

Homework Equations


How much power does it emit per square meter? W
What is its wavelength of peak intensity? nm

The Attempt at a Solution



i am looking for the equations to calculate this thing:confused:
 
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  • #2
Gh0stman said:

Homework Statement



Consider a 5.50×10 (to the 4th power) object that emits thermal radiation.

What does this number describe about the object? I.e what are the units?

Homework Equations


How much power does it emit per square meter? W
What is its wavelength of peak intensity? nm

The Attempt at a Solution



i am looking for the equations to calculate this thing:confused:

I would guess you have been learning about the Stefan-Boltzman law and Wien's displacement law.
 
  • #3


Hello,

The thermal radiation law, also known as the Stefan-Boltzmann law, states that the power emitted per unit area by a black body is proportional to the fourth power of its absolute temperature. The equation for this law is given by P = σAT^4, where P is the power emitted, σ is the Stefan-Boltzmann constant (5.67 x 10^-8 W/m^2K^4), A is the surface area of the object, and T is the absolute temperature in Kelvin.

To calculate the power emitted per square meter, you can use the above equation and plug in the values given in the problem. So, P = (5.67 x 10^-8 W/m^2K^4) x (5.50 x 10^4 K)^4 = 2.78 x 10^14 W/m^2.

To find the wavelength of peak intensity, you can use Wien's displacement law, which states that the wavelength of maximum intensity (λmax) is inversely proportional to the absolute temperature. The equation for this law is given by λmax = b/T, where b is the Wien displacement constant (2.90 x 10^-3 mK). So, in this case, λmax = (2.90 x 10^-3 mK)/(5.50 x 10^4 K) = 5.27 x 10^-8 m = 52.7 nm.

I hope this helps you with your homework. Let me know if you have any further questions. Good luck!
 

FAQ: What Equations Calculate Thermal Radiation and Wavelength Peak Intensity?

What is the thermal radiation law?

The thermal radiation law, also known as the Stefan-Boltzmann law, is a physical law that describes the relationship between the temperature of an object and the amount of thermal radiation it emits. It states that the total energy radiated per unit time by a black body is directly proportional to the fourth power of its absolute temperature.

What is a black body?

A black body is an ideal object that absorbs all of the radiation that falls on it and emits thermal radiation at all wavelengths. It is used as a theoretical model to understand the behavior of real objects that emit thermal radiation.

How is the thermal radiation law used in practical applications?

The thermal radiation law is used in various practical applications, such as in thermodynamic calculations, in the design of thermal insulation and heat transfer systems, and in the development of technologies that utilize thermal radiation, such as solar panels and infrared cameras.

What factors affect the amount of thermal radiation emitted by an object?

The amount of thermal radiation emitted by an object is affected by several factors, including the object's temperature, surface area, and emissivity (ability to emit radiation). The type of material and its reflective properties also play a role in the amount of thermal radiation emitted.

How does the thermal radiation law relate to the greenhouse effect?

The thermal radiation law is the basis for understanding the greenhouse effect, which is the process by which Earth's atmosphere traps heat from the sun. The gases in the atmosphere act as a blanket, absorbing and re-emitting thermal radiation, which helps to keep the Earth's surface warm enough to support life.

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