Two planets move around the sun. The periodic times and the mean radii of the orbits are $T_1, T_2$ and $r_1, r_2$ respectively. The ratio $T_1/T_2$ is equal to

How will you 'weigh the sun',that is estimate its mass? The mean orbital radius of the earth around the sun is $1.5 \times 10^{8} \text{ km}$.

The time period of a satellite of the Earth is $5 \text{ hours}$. If the separation between the Earth and the satellite is increased to four times the previous value, the new time period of the satellite will be: (in $\text{ hours}$)

The distances of Neptune and Saturn from the Sun are nearly $10^{13} \ m$ and $10^{12} \ m$ respectively. Assuming that they move in circular orbits,their periodic times will be in the ratio:

$A$ planet moving around the Sun sweeps out an area $A_{1}$ in $2$ days,$A_{2}$ in $3$ days,and $A_{3}$ in $6$ days. Then,the relation between $A_{1}, A_{2}$,and $A_{3}$ is

The Earth revolves around the Sun in one year. If the distance between them becomes double,the new period of revolution will be