Show that the escape velocity of a body from the surface of a planet of radius R and mean density `rho` is `Rfrac(sqrt8pirhoG)(3)`
OR
Show that the escape velocity of a body from the surface of the earth is `2Rfrac(sqrt2pirhoG)(3)`, where R is the radius of the earth and `rho is the mean density of the earth.
OR
Obtain formula of escape velocity of a body at rest on the earth's surface in terms of mean density of erth.