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Need help with finding densityby mendem03
Tags: density 
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#1
Nov2011, 07:09 PM

P: 14

1. The problem statement, all variables and given/known data
Assuming the Earth to be comprised of only a uniform density mantle and a uniform density core and the mean density of the mantle to be 4700 kg=m3, determine the mean density of the Earth's core. Take Earth's radius to be 6400 km and the radius of the core to be 3500 km. Assume the Earth's mean density is 5520 kg=m3 2. Relevant equations density = mass/volume 3. The attempt at a solution V_c = 1.80 * 10^20 meter cubed V_e = 1.10 * 10^21 meter cubed V_m = V_e  V_c = 9.20 * 10^20 M_e = M_c + M_m M_e = D_c*V_c + D_m*V_m D_c = (M_e  D_m*V_m)/V_c D_c = 9222.22 I think I got the wrong answer so can someone help me with it. 


#2
Nov2011, 09:32 PM

P: 6

From the givens, I got
D_c = (M_e  M_m) / V_c = [ D_e*V_e  ((D_m (V_e  V_c)) ] / V_c which is equivalent to yours and an answer, though slightly different, of the same order of magnitude. 


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