Practice question
Question
A moon orbits a planet with a period of 13 days and radius 1.0×109m. What is the planet’s mass? (G\=6.67×10−11N m2/kg2,1day\=86400s)
Explanation
M = 4π2r3GT2. T = 13×86400 = 1.1232×106s. T2 = 1.262×1012s2. r3 = (1.0×109)3 = 1.0×1027m3. M = 4×(3.14)2×10276.67×10−11×1.262×1012. M = 3.947×10278.418×101≈4.69×1025kg. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 4.7 × 10²⁵ kg. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Discussion
Comments
Share your thoughts. New comments appear after admin approval.
Please log in to join the discussion.
Login to commentNo comments yet. Be the first to start the discussion.