JEE Main 2025 Physics question
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The radius vector from the Sun to a planet sweeps out equal areas in equal intervals of time and thus areal velocity of planet is constant. Reason (R) : For a central force field the angular momentum is a constant. In the light of the above statements, choose the most appropriate answer from the options given below.
Answer: (3)
Solution
dA/dt = L/2m = constant since angular momentum is conserved in central force field; this explains Kepler's second law.