Question

The earth rotates about the sun in an elliptical orbit as shown in figure. At which point its velocity will be maximum?

• A. At C
• B. At A
• C. At D
• D. At B

Answer 1

Answer: (B)

At A

$Answer:-$ B

The gravitational potential energy of the earth is lowest (most negative) when it is closest to the sun. To a good approximation, the only force on the earth is from the sun. Since the mechanical energy (kinetic energy + potential energy) of the earth has to be conserved in this approximation, the kinetic energy has to be the highest when it is closest to the sun, implying that the orbital velocity has to be highest as well.