Question

Out of aphelion and perihelion, where is the speed of the earth more and why?

Answer 1

Aphelion is the location of the earth where it is at the greatest distance from the sun and perihelion is the location of the earth where it is at the nearest distance from the sun.

Aphelion is the location of the earth where it is at the greatest distance from the sun and perihelion is the location of the earth where it is at the nearest distance from the sun.

The perihelion and aphelion locations for earth can be as shown in the diagram


According to the Kepler's second law, areal velocity is constant.

So, ${\gamma }_p\times v_p={\gamma }_A\times v_A$

$\frac{{\gamma }_A}{{\gamma }_p}=\frac{v_p}{v_A}$

Therefore, ${\gamma }_A>{\gamma }_p.$

So, $v_p>v_A$

Therefore, the speed of the earth is more at the perihelion than at the aphelion.
According to Kepler’s second law of planetary motion at perihelion the earth has to cover greater linear distance to keep the areal velocity constant.

Final answer: The speed of the earth is more at the perihelion than at the aphelion.