Assuming the earth to be a sphere of radius 6370 km, how many square kilometers is area of the land, if three-fourth of the earth’s surface is convered by water.

How much surface of earth is covered by water ?

Assuming the earth to be a sphere of uniform mass density, how much would a body weigh half way down to the centre of the earth if it weighed 250 N on the surface ?

At what height acceleration due to gravity is three-fourths of that at the surface of earth?

Earth can be thought of as a sphere of radius 6400 km.Any object (or a person) is pewrforming circular motion around the axis of the earth due to the earth rotation (period 1 day). What is acceleration of object on the surface of the earth (at equator) towards its centre? What is it at latitude theta ? How does these acceleration compare with g = 9.8 m//s^(2) ?

What will be the corresponding expression for the energy needed to completely diassemble the planet earth against the gravitational pull amongst its constituent particles? Assume the earth to be a sphere of uniform mass density. calculate the energy, given that the product of the mass and the radius of the earth to be 2.5xx10^(31)kg-m

Assuming the earth to be a sphericl conductor of radius 6400 km, calculate its caacitance. Given 1/(4piepsilon_0) = 9 xx 10^9 Nm^2^-2

A right circular cylinder just encloses a sphere of radius r. Find (i) surface area of the sphere, (ii) curved surface area of the cylinder, (iii) ratio of the areas obtained in (i) and (ii). Assume pi = 22/7

Assuming that the earth’s radius is 6400 km and that it subtends an angle of 57’ at the centre of the moon, find the distance of the centre of the moon from the earth’s centre.