Solve Radiation Problem: Find Temp as Function of Time

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SUMMARY

The discussion focuses on solving a radiation problem to find the temperature of a satellite sensor as a function of time. The sensor has a longwave absorptivity (a_LW) of 0.8 and shortwave absorptivity (a_SW) of 0.2, with an area of 0.3 m² and specific heat of 4 J/K. The equilibrium temperature is calculated using the formula T = ((a_sw/a_LW)*(Fs/omega))^1/4, where Fs is the solar flux (1368 W/m²) and omega is the Stefan-Boltzmann constant. The equation for temperature as a function of time is m*c*(dT/dt) = A*omega*T^4, where the mass (m) is considered negligible due to the small size of the sensor.

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Physics-101
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Homework Statement


We have a sensor onboard a satellite that is faced towards Earth, from the Sun. The LW absorptivity is 0.8 (a_LW) and SW is 0.2 (a_SW).
I need to find a equation for the temperature as a function of time. Given datas is the Area=0.3 m^2 and Specific Heat of 4 J/K

Homework Equations


See below.

The Attempt at a Solution


I think that I need to calculate the equilibrium temperature, which I did by using T=((a_sw/a_LW)*(Fs/omega))^1/4,
Fs=solar flux=1368 W/m^2 and omega= Stefan-Boltsmann constant.

Later, one equation that I have in mind for the temperature as a function of time is:
m*c*(dT/dt)=A*omega*T^4 , where A= area and m= mass. The sensor might be really small, so the mass m is negligible (?). What should I do now, I'm stuck.

Thanks!
 
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Have you thought of anything else to help solve the problem?
 
Physics-101 said:
Later, one equation that I have in mind for the temperature as a function of time is:
m*c*(dT/dt)=A*omega*T^4 , where A= area and m= mass. The sensor might be really small, so the mass m is negligible (?).
A negligible mass is equivalent to a satellite that is always at its equilibrium temperature .

You'll have different areas for absorption of sunlight and emission of infrared light, and those areas depend on the orientation of the satellte.
 

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