At what height above the Earth's surface does the acceleration due to gravity become $1\%$ of its value at the Earth's surface (in $R$)? (Radius of Earth $= R$)

At a height of $h$ $km$ from the surface of the Earth,the gravitational potential and the value of $g$ are $-5.4 \times 10^7\, J kg^{-1}$ and $6.0\, m s^{-2}$ respectively. Take the radius of the Earth as $6400\, km$.

What is the acceleration due to gravity at a distance of $2R$ from the surface of the Earth,where $R$ is the radius of the Earth?

At what altitude in metres will the acceleration due to gravity be $25\%$ of that at the earth's surface? (Radius of earth $= R \ m$)

When a body is taken from the pole to the equator,its weight:

$Assertion$ : In a free fall,the weight of a body becomes effectively zero.
$Reason$ : The acceleration due to gravity acting on a body in free fall is zero.