Average density of the earth

For what value of the angular velocity of the earth, the acceleration due to gravity in the equatorial region would have been zero ? The average density of the earth's material =5.5 g*cm^(-3) and G=6.67xx10^(-8) CGS unit. Find the ratio of this calculated value and the present value of the angular velocity of the earth.

Average density of earth

The time period 'T' of the artificial satellite of earth depends on the average density rho of the earth as

The magnitude of the average electric field normally present in the earth's atmosphere just above the surface of the earth is about 150 N/C, directed downward. What is surface charge density of the earth? [Assume that the earth is a conductor having uniform surface charge density.]

Average density of earth is

Calculate the average density of earth in terms of g, G and R.