Q99 / 180 · NEET 2018 · Physics

The kinetic energies of a planet in an elliptical orbit about the Sun, at positions, $A, B$ and $C$ are $K_{A}, K_{B} a n d K_{C}$ , respectively. $A C$ is the major axis and $S B$ is perpendicular to $A C$ at the position of the Sun $S$ as shows in the figure. Then

Solution

By angular momentum consentration about the sun,

L = I ω =

constant

K E = \frac{L^{2}}{2 I}

∵ S A ∠ S B ∠ S C

\Rightarrow

I_{A} < I_{B} < I_{C}

{K E}_{A} > {K E}_{B} > {K E}_{C}

Hence, the correct answer is option: 'B'.