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astrofunk21
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Homework Statement
Use equation 1.3 to estimate the solar radius Ro from its luminosity and effective temperature. Show that the gravitational acceleration g at the surface is about 30 times larger than that on Earth.
Homework Equations
(1.3) L=4∏R2σSBT4
The Attempt at a Solution
Well we know the gravity of something can be determined through g=[itex]\frac{-GM}{r*r}[/itex]. Solving for r in the gravitational equation will allow us to substitute that into the luminosity equation. With all of those known, we can solve for g and see how it is 30 times larger. This however did not work. My answer was -27.79 m*s-2.
Now since this number is pretty much off by a factor of ten, I feel that I'm on the right track. Maybe I messed something up in my calculation that you guys will see. My substitution will be below if it helps.
1. L=4∏R2σSBT4
2. g=[itex]\frac{-GM}{r*r}[/itex]
3. r2=[itex]\frac{-GM}{g}[/itex]
4. L=4∏[itex]\frac{-GM}{g}[/itex]σSBT4
5. g=[itex]\frac{-GMT^{4}4∏σ}{L}[/itex]
6. Then solve for g!
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