Question

A point mass $m$ is placed inside a spherical shell of radius $R$ and mass $M$ at a distance $\frac{R}{2}$ from the centre of the shell. The gravitational force exerted by the shell on the point mass is

• A. $\frac{GMm}{R^{2}}$
• B. $\frac{2GMm}{R^{2}}$
• C. zero
• D. $\frac{4GMm}{R^{2}}$

Answer 1

Answer: (C)

zero

Answer 2

If a point mass is placed inside a uniform spherical shell, the gravitational force on the point mass is zero. Hence, the gravitational force exerted by the shell on the point mass is zero.