The largest and the shortest distance of the earth from the sun are ${r_1}$ and ${r_2}$, its distance from the sun when it is at the perpendicular to the major axis of the orbit drawn from the sun
$\frac{{{r_1} + {r_2}}}{4}$
$\frac{{{r_1}{r_2}}}{{{r_1} + {r_2}}}$
$\frac{{2{r_1}{r_2}}}{{{r_1} + {r_2}}}$
$\frac{{{r_1} + {r_2}}}{3}$
Two heavenly bodies ${S_1}$ and ${S_2}$, not far off from each other are seen to revolve in orbits
Suppose there existed a planet that went around the sun twice as fast as the earth. What would be its orbital size as compared to that of the earth ?
Two planets $A$ and $B$ of equal mass are having their period of revolutions $T_{A}$ and $T_{B}$ such that $T_{A}=2 T_{B}$. These planets are revolving in the circular orbits of radii $I_{A}$ and $I_{B}$ respectively. Which out of the following would be the correct relationship of their orbits?
If the earth suddenly shrinks to $\frac{1}{64}$ th of its original volume with its mass remaining the same, the period of rotation of earth becomes $\frac{24}{ x } h$. The value of $x$ is $.......$