Question

The earth rotates around the sun in elliptical orbit as shown in the figure.

Where is the velocity of the earth the maximum?

• A. At X
• B. At Z
• C. At W
• D. At Y

Answer 1

The correct option is C

At W

Law of Equal Areas from the three Keplar’s Law states that, “An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time”. In order to sweep equal areas at points W, X, Y and Z in equal time intervals, the planet needs to travel maximum distance in case of point W. Hence, its speed is maximum at W.

(for shaded regions to be equal in area, $X_1$>$X_2$)