Two satellites,$A$ and $B,$ have masses $m$ and $2m$ respectively. $A$ is in a circular orbit of radius $R,$ and $B$ is in a circular orbit of radius $2R$ around the earth. The ratio of their kinetic energies,$K.E._A / K.E._B ,$ is

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

$A$ geostationary satellite is taken to a new orbit such that its distance from the centre of the earth is doubled. Find the time period of this satellite in the new orbit.

$A$ comet orbits the Sun in a highly elliptical orbit. Does the comet have a constant $(a)$ linear speed,$(b)$ angular speed,$(c)$ angular momentum,$(d)$ kinetic energy,$(e)$ potential energy,$(f)$ total energy throughout its orbit? Neglect any mass loss of the comet when it comes very close to the Sun.

Obtain an equation for the orbital time period of a satellite revolving around the Earth.

$A$ satellite is to revolve around the Earth in a circle of radius $8000\, km$. The speed at which this satellite must be projected into an orbit will be......... $km/s$.