The time period of polar satellites is about ..........

Two satellites are launched simultaneously into orbits of radius $R$ and $4R$. At an instant,the two satellites are on the same radial line. The time after which they have maximum separation is (mass of Earth = $M_e$). Assume the same sense of rotation.

$A$ satellite of the earth is revolving in a circular orbit with a uniform speed $v$. If the gravitational force suddenly disappears,the satellite will

The height of a geostationary satellite is approximately ........ $km$.

$A$ body is projected with a velocity greater than orbital velocity but less than escape velocity. Its path is

The orbital period of a geostationary satellite is (in $\,h$)