Question

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 $\left(dA/dt\right)=\left(r^2\omega \right)/2$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect and Reason is correct

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Assertion Kepler's second law can be understoud by conservation of angular momentum principle.

Reason : Kepler's second law is related with a real velocity which can further be proved to be correct based on conversation of angular momentum.

So, we now according to Kepler's law $\frac{dA}{dt}=$ constant

As $\frac{dA}{dt}=\frac{1}{2}{r}^2\frac{d\theta }{dt}=\frac{1}{2}{r}^{2}w$

$\therefore$ $\frac{{Mr}^{2}w}{2M}=\frac{L}{2m}=$ constant

$\therefore$ $L=$ constant

So, Option $\left(a\right)$ so both assertion and reason are correct and reason is correct explanation for assertion.