NEET2017PhysicsGravitationActual
Assertion : Kepler's second law can be understood by conservation of angular momentum principle. Reason : Kepler's second law is related with areal velocity which can further be proved to be based on conservation of angular momentum as (d A / d t)= (r^2 ) / 2 .
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of assertion.
Step-by-step solution
According to Kepler's law, d A d t = constant As, d A d t = 1 2 r^2 d d t = 1 2 r^2 aligned & m r^2 2 m = L 2 m = constant & L= constant aligned