Question

Two concentric spherical shells have masses M1, M2 and radii R1, R2 (R1 < R2). What is the force exerted by this system on a particle of mass m1 if it is placed at a distance (R1 + R2)/2 from the centre?

Answer 1

Explanation:

• It is given that the particle of mass  $m_1$ is placed at a distance $\frac{R_{1}+R_{2}}{2}$ from the centre.  
• The gravitational force of the particle due to shell with mass  $M_2$ is zero as the particle is located outside the shell of mass  $M_1$ and inside the shell of mass $M_2$.  That is, the particle is located in between these two con centric spherical shells as $R_2>R_1$ .
• Therefore, the gravitational field due to the shell of mass $M_{2}=\frac{C M_{1} m_{1}}{\left(\frac{R_{1}+R_{2}}{2}\right)^{2}}$ .  Which on solving, we get $\frac{4 C M_{2} m_{1}}{\left(R_{1}+R_{2}\right)^{2}}$  .

Answer 2

Explanation:

Hope this will help you ☺️