Physics: Conduction, Convention, Radiation?

The Earth has a surface temperature around 270 K and an emissivity of 0.8, while space has a temperature of around 2 K.

Use Stefan\'s law: P(net) = 5.67×10-8 W/K4 m2 *A*e*(T4 - To4) to solve the following questions.

(Radii of the Earth and the Sun are Re = 6.38×106 m, Rs = 7×108 m.)

3) If the energy absorbed by the Earth from the Sun constitutes only 1/(1010) of the Suns total radiant energy to the space, and consider the Sun is a black body, what is the surface temperature of the Sun in Kelvin K?

T_sun =

I've tried this a million times, please help!

Here's the image:

2 Answers

  • 8 years ago
    Favorite Answer

    You have to do this in 2 stages.

    Assuming the heat lost by the earth by radiation is equal to the heat gained by the earth by radiation from the sun.... you know the earth's temperature, surface area (from the radius), emissivity and the background temperature, so you can find the total heat lost by the earth.

    This heat lost is 1/1010 of the heat generated by the sun, so you know how much heat is generated by the sun. From this you can work out the sun's surface temperature since you can work out the sun's surface area and you know its emissivity and you know the background temperature.

  • 4 years ago

    If some thing conducts then warmth runs by it, or electricity, so the debris are more effective energetic and characteristic more effective kinetic power. Radiation is even as it provides out warmth to our surroundings making debris round it more effective energetic

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