If $M$ is mass of a planet and $R$ is its radius then in order to become black hole [ $c$ is speed of light]
$\sqrt{\frac{G M}{R}} \leq c$
$\sqrt{\frac{G M}{2 R}} \geq c$
$\sqrt{\frac{2 G M}{R}} \geq c$
$\sqrt{\frac{2 G M}{R}} \leq c$
At what altitude will the acceleration due to gravity be $25\% $ of that at the earth’s surface (given radius of earth is $R$) ?
Two spheres of masses $m$ and $M$ are situated in air and the gravitational force between them is $F$. The space around the masses is now filled with a liquid of specific gravity $3$. The gravitationalforce will now be
Maximum height reached by an object projected perpendicular to the surface of the earth with a speed equal to $50\%$ of the escape velocity from earth surface is - ( $R =$ Radius of Earth)
Suppose the gravitational force varies inversely as the nth power of distance. Then the time period of a planet in circular orbit of radius $R$ around the sun will be proportional to
A body weighs $72\, N$ on the surface of the earth. What is the gravitational force(in $N$) on it, at a helght equal to half the radius of the earth$?$