What is the meaning of “anchoring earth” and “earth cave”?

What is earthing?

Is there any meaning of Weight of the earth?

Is there any meaning of Weight of the earth?

If rho is the mean density of the earth and R is its radius, then the critical speed of a satellite revolving very close to the surface of earth is :

What is the strength of earth's magnetic field at the surface of earth?

A body weighs 63 N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth ?