Question

As shown in figure, a planet revolves in elliptical orbit around the sun. Where is KE of the planet maximum?

• A. At $P_4$
• B. At $P_1$
• C. At $P_2$
• D. At $P_3$

Answer 1

The Correct Option is A

By the Iaw of conservation of anguiar momentum, we have
$\hspace30mm J = I \omega =$ constant
where, I is moment of inertia and co is angular velocity.
Also, $\hspace15mm I = MR^2$ and $\omega = \frac{v}{R}$
$\therefore \hspace30mm v \propto \frac{1}{R} $
At $P_4$ the value of R is minimum, hence the velocity is

maximum or kinetic energy will be maximum.