A 250kg satellite orbits Earth at 6RE from the center. What is its total energy? (ME\=6×1024kg,RE\=6.4×106m,G\=6.67×10−1
E = −GMEm2r. r = 6RE = 3.84×107m. E = −6.67×10−11×6×1024×2502×3.84×107. E = −1.001×10177.68×107≈−1.30×109J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to -1.3 × 10⁹ J. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: Halliday & Resnick, Fundamentals of Physics, 11th ed., Chapter 13: Gravitation.