Question

Figure shows a planet in an elliptical orbit around the Sun $S$. Where is the kinetic energy of the planet maximum?

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

Answer 1

The correct option is D $P_4$

For angular momentum to be constant, $mvr=constant$

Thus $v\propto \frac{1}{r}$ means $v$ is maximum where $r$ is minimum

As $r$ at $P_4$ is minimum $⟹v_{P4}$ is maximum

Also, $K.E=\frac{1}{2}m{v}^2$

Hence, $K.E$ is maximum at $P_4$