Question

How to find density of earth for class 11?

Answer 1

Density of earth is 9.8
density=mass÷volume

Answer 2

We have the relation F = GmM/R2 = mg, where F is the gravitational force, G is the gravitational constant, M is the mass of the Earth, R is the radius of the Earth, and m is the mass of another object (near the surface of the Earth).  Cancelling m on both sides, we get GM/R2= g.   M = gR2/G,  where g = 9.8 m/s2,  R = 6.4 x 106 m, and G = 6.67 x 10-11 m3/(kg s2).   M = 9.8 x (6.4 x 106)2/(6.67 x 10-11) = 6.0 x 1024 kg  Density of earth = Mass of earth /Volume of earth                              D = M/V V = 4πR3/3     = 4 x 3.14 x (6.4 x 106 )3/3     =  1097.5 x 1018 m3. D = M/V =  6.0 x 1024 kg / 1097.5 x 1018 m3.               =  5.466 x 103 kg/m3.