Gravitation - Result Question 1
1. The kinetic energies of a planet in an elliptical orbit about the Sun, at positions $A, B$ and $C$ are $K_A, K_B$ and $K_C$, respectively. $AC$ is the major axis and $SB$ is perpendicular to $AC$ at the position of the Sun $S$ as shown in the figure. Then
[2018]
(a) $K_A<K_B<K_C$
(b) $K_A>K_B>K_C$
(c) $K_B>K_A>K_C$
(d) $K_B<K_A<K_C$
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Solution:
- (b) Speed of the planet will be maximum when its distance from the sun is minimum as $m v r=$ constant.
Point $A$ is perihelion and $C$ is aphelion.
Clearly, $V_A>V_B>V_C$
So, $K_A>K_B>K_C$
