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icedragon
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Homework Statement
What is the apparent magnitude of a 100W light bulb at a distance of 3 m?
[Hint: Compare with the Sun to eliminate the unknown constant in the expression relating flux density to apparent magnitude.]
. The solar luminosity is [itex]L \approx 4 \times 10^{26} W[/itex].
. The Earth-Sun distance is approximately [itex]1.5 \times 10^8 km[/itex].
Homework Equations
[itex]m-M=5log \frac{d}{10}[/itex]
[itex]m=-2.5log \frac{l}{l_{0}}[/itex]
The Attempt at a Solution
I have attempted to substitute m into the equation for m-M but I do not see how that helps me eliminate the unknown constant (which I assume is [itex]l_{0}[/itex]. Any help would be appreciated!
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