A thin spherical shell has mass M and radius R. What is the gravitational potential inside the shell at distance r from the centre (r < R)?
Answer and explanation
Correct answer: A. V = -G*M / R
- Step 1: Inside a spherical shell, gravitational field strength g = -dV/dr = 0 by Gauss's law. Step 2. Since the field is zero, the gravitational potential V is constant throughout the interior, equal to -GM/R. *Answer: V = -GM / R. Why not the others:** Potential does not vanish inside; rather, its gradient (the field) vanishes.
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