Physics Help Forum Density of Black Hole

 Special and General Relativity Special and General Relativity Physics Help Forum

 Oct 4th 2018, 01:57 PM #1 Junior Member   Join Date: Sep 2018 Posts: 7 Density of Black Hole So when I tested the sample question I got the right answer. But doing a practice one I feel like I got the wrong answer - it seems way too high: Black hole mass - 4.31 x 10^6 I calculated Rs to be = 1.27 x 10^7 Average density: P = m/v m = (4.31x10^6) x (1.989x10^30) m = 8.57x10^36 km v=4/3 x π x r^3 v= 4.3 x π x (4.127x10^7)^3 v= 8.22 x 10^21 P = (8.57x10^26) / (8.22 x 10^21) P = 1.04 x 10^15 km m^-3 Have I calculated this correctly or have I done something wrong? When I go on to look a Roche Limit: 1400 kg m^-1 = Sun's average density r = 2.456(((1.04x10^15)/(1400))^1/3) r = 2243.17 Which seems way too high?

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