Question

A particle fo mass 100 g is kept on the surface of a uniform sphere of mass 10 kg and radius 10 cm. find the work to be done against the gravitational force between them to take the particle away from the sphere.

Answer 1

Work done against gravitational force to take away the particle from sphere,
$=\frac{G\times 10\times 0.1}{1\times 0.1}=\frac{6.67\times {10}^{-11}\times 1}{1\times 0.1}=6.57\times {10}^{-10}j$