A body weighs 147N on Earth’s surface. What is its weight at a height h\=RE/3? (g\=9.8m/s2)
g(h) = g(1+h/RE)2. h = RE/3, 1+h/RE = 4/3. g(h) = 9.8(4/3)2 = 9.8×916 = 5.51m/s2. Mass: m = 147/9.8 = 15kg. Weight: W = 15×5.51≈82.7N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 83 N. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
