Calculate Earth's Net Power Output to Space

[mattmannmf]

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.)

(a) What is the net power radiated from our Earth into free space in Watt W?

I came up with an answer of 1.54*10^17...is that what you came up with? (just use the equation mentioned above and A=4*Pi*Re2, e=.8, T= 270, To=2)

 

[LowlyPion]

Looks like the right values to input. Estimating it with orders of magnitude looks about right.

 

[nlightner]

Yes, I also calculated the net power output to be approximately 1.54*10^17 W. This value represents the amount of energy that the Earth is radiating into space, taking into account the Earth's surface temperature, emissivity, and the temperature of space. This value is significant as it shows the amount of energy that the Earth is constantly losing to maintain its overall temperature.