The angular momentum of a planet of mass $M$ moving around the sun in an elliptical orbit is $\overrightarrow{ L }$. The magnitude of the areal velocity of the planet is:

The planet Mars has two moons, if one of them has a period $7\, hours,\, 30\, minutes$ and an orbital radius of $9.0 \times 10^{3}\, {km} .$ Find the mass of Mars.

$\left\{\operatorname{Given} \frac{4 \pi^{2}}{G}=6 \times 10^{11} {N}^{-1} {m}^{-2} {kg}^{2}\right\}$

Which of the following quantities does not depend upon the orbital radius of the satellite

The period of revolution of planet $A$ around the sun is $8$ times that of $B$. The distance of $A$ from the sun is how many times greater than that of $B$ from the sun

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.