A satellite of mass m is at a distance of $'a'$ from a star of mass $M.$ The speed of the satellite is $u.$ Suppose the law of universal gravity is $F=-G\frac{Mm}{r^{2.1}}$ instead of $F=-G\frac{Mm}{r^{2}}$ find the speed of the satellite when it is at $a$ distance $b$ from the star.

Potential energy of a satellite having mass $‘m’$ and rotating at a height of $6.4 \times {10^6}\,m$ from the earth surface is

Let escape velocity of a body kept at surface of a planet is $u$. If it is projected at a speed of $200 \%$ more than the escape speed, then its speed in interstellar space will be ………..

In order to shift a body of mass $m$ from a circular orbit of radius $3R$ to a higher radius $5R$ around the earth, the work done is

What is the magnitude of potential energy at infinity distance ?