Physics - Gravitation Question with Solution | TestHub

Given a thin homogeneous disc of radius a and mass ${\mathrm{m}}_1$. A particle of mass ${\mathrm{m}}_2$ is placed at a distance $\ell$ from the disc on its axis of symmetry. Initially both are motionless in free space but they ultimately collide because of gravitational attraction. Assuming a $\ll \ell$, find the relative velocity at the time of collision.