The periodic time of a satellite revolving above Earth's surface at a height equal to $R$ (where $R$ is the radius of the Earth) is given by (where $g$ is the acceleration due to gravity at Earth's surface):

The centripetal force acting on a satellite orbiting around the Earth and the gravitational force of the Earth acting on the satellite are both equal to $F$. The net force on the satellite is

If a satellite is orbiting the earth very close to its surface,then the orbital velocity mainly depends on

The radii of circular orbits of two satellites $A$ and $B$ of the earth are $4R$ and $R,$ respectively. If the speed of satellite $A$ is $3V,$ then the speed of satellite $B$ will be ...... $V$.

The International Space Station is maintained in a nearly circular orbit with a mean altitude of $330 \, km$ and a maximum of $410 \, km$. An astronaut is floating in the space station's cabin. The acceleration of the astronaut as measured from the Earth is:

The distance between two stars of masses $3 M_S$ and $6 M_S$ is $9 R$. Here $R$ is the mean distance between the centers of the Earth and the Sun,and $M_S$ is the mass of the Sun. The two stars orbit around their common center of mass in circular orbits with period $n T$,where $T$ is the period of Earth's revolution around the Sun. The value of $n$ is. . . . .