Question

Two identical spheres are placed in contact with each other. The force of gravitation between the spheres will be proportional to (R = radius of each sphere)

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

$F=G\frac{M\times M}{R^2}=\frac{G\times {\left(\frac{4}{3}\pi R^3\rho \right)}^2}{(2R{)}^2}\Rightarrow F\propto \frac{R^6}{R^2}\propto R^4$