The ratio of the accelerations due to gravity at heights 1280 km and 3200 km above the surface of the earth is (Radius of the earth $=6400 \mathrm{~km}$ )

Regarding fundamental forces in nature, the correct statement is

The energy required to take a body from the surface of the earth to a height equal to the radius of the earth is $W$. The energy required to take this body from the surface of the earth to a height equal to twice the radius of the earth is

A body of mass $m$ is at height $R$ from the surface of the earth where $R$ is the radius of the earth. If the body is taken from here to a height of $3 R$ from the surface of the earth, the increase in the gravitational potential energy of the body is

( $g$ is acceleration due to gravity on the surface of the earth)