How much energy is required to move a 300kg satellite from 7RE to 14RE from Earth’s center? (ME\=6×1024kg,RE\=6.4×106m,G
ΔE = −GMEm(1r2−1r1). r1 = 4.48×107m, r2 = 8.96×107m. ΔE = −6.67×10−11×6×1024×300(18.96×107−14.48×107). ΔE = −1.201×1017(−1.116×10−8)≈1.34×109J. 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 A is scientifically correct.
Ref: Halliday & Resnick, Fundamentals of Physics, 11th ed., Chapter 13: Gravitation.