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astronut77 astronut77
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10 years ago
The Sun radiates a total power of about 4×1026 watts into space. The Sun's radius is about 7×108 meters.

A.) Calculate the average power radiated by each square meter of the Sun's surface. (Hint: The formula for the surface area of a sphere is A=4πr2.)

a.    ≈2×108Wm2
b.    ≈2×1045Wm2
c.    ≈5×1016Wm2
d.    ≈6×107Wm2


B.) Using your answer from part A and the Stefan-Boltzmann law, calculate the average surface temperature of the Sun. (Note: The temperature calculated this way is called the Sun's effective temperature.)


a.    ≈6,000K
b.    ≈1,000K
c.    ≈1015K
d.    ≈10,000K
Source  Mastering Astronomy
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Staff Member
Educator
10 years ago
HI astronut77,

I tried looking up the answers to these question, but no luck. Did you end up finding the answers to them? I'd like to know what you got, if that's OK.
Mastering in Nutritional Biology
Tralalalala Slight Smile
wrote...
Donated
10 years ago
I get D for number one. You take the total wattage emitted (4x10^26w) and divide by the surface area (4π(7x10^8)^2 m^2) and end up with 6.49612x10^7 w/m^2.

Don't know how to do number two, but the Sun's effective temperature is 5780K, so A for that one.
wrote...
Staff Member
Educator
10 years ago
Thanks Connor
Mastering in Nutritional Biology
Tralalalala Slight Smile
wrote...
Donated
10 years ago
No problem.
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