A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in new orbit is $2$ times that of the earlier orbit. The time period in the second orbit is

A satellite $S$ moves around a planet $P$ in an elliptical orbit as shown in figure. The ratio the speed of the satellite at point $a$ to that at point $b$ is

A planet moving along an elliptical orbit is closest to the sun at a distance $r_1$ and farthest away at a distance of $r_2$. If $v_1$ and $v_2$ are the linear velocities at these points respectively, then the ratio $\frac{v_1}{v_2}$ is

A satellite moves in a circle around the earth. The radius of this circle is equal to one half of the radius of the moon’s orbit. The satellite completes one revolution in

The time period of a geostationary satellite is $24\; \mathrm{h}$, at a helght $6 \mathrm{R}_{\mathrm{E}}( \mathrm{R}_{\mathrm{E}}$ is radius of earth) from surface of earth. The time period of another satellite whose helght is $2.5 \mathrm{R}_{\mathrm{E}}$ from surface will be

The satellite of mass $m$ revolving in a circular orbit of radius $r$ around the earth has kinetic energy $E$. Then its angular momentum will be