ASTRONOMY MATH PROBLEM!?
Can you help me solve this?
-Suppose the number density of galaxies in the universe is on average 3 x 10^-68 galaxies per cubic meter. If astronomers could observe all galaxies out to a distance of 10^10 light years, how many galaxies would they find
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r = [10]ly
ϱ = 3[-68] Glx/m³
ly = 9.46[15] m
r = 9.46[25] m
V_sphere = 4.189r³
V = 4.189(9.46[25])³
V = 4.189(8.47[77])
V = 3.55[78] m³
Glx = Vϱ = 3.55[78] • 3[-68] = 1.07[11]
Answer: 100 billion galaxies.
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i am not sure what iam saying is right but
shouldnt your find how many galaxies there are within the distance of 10 x 10 light years away and multiply it by average mass of a galaxy ?