Question

Which of the following quantities remain constant in a planetory motion (consider elliptical orbits) as seen from the sun?

• A. Speed
• B. Angular speed
• C. Kinetic energy
• D. Angular momentum

Answer 1

The correct option is D Angular momentum

As $\tau =I\frac{d\omega }{dt}$
Torque is zero.
So, angular momentum remains constant.