Practice question
Question
A body weighs 196N on Earth’s surface. What is its weight at a depth d\=RE/4? (g\=9.8m/s2)
Explanation
g(d) = g(1−d/RE). d = RE/4, g(d) = 9.8(1−1/4) = 9.8×3/4 = 7.35m/s2. Mass: m = 196/9.8 = 20kg. Weight: W = 20×7.35 = 147N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 147 N. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.