To calculate the gravitational force exerted by a semicircular rod on a point mass at its center of curvature, it's essential to consider the contributions from each infinitesimal mass segment along the rod. The symmetry of the semicircle means that the horizontal components of the gravitational forces will cancel out, leaving only the vertical components to be summed. This can be achieved by breaking the rod into small mass elements (dm) and integrating the y components of the forces they exert. The integration is most effectively performed by converting the mass distribution into an angle-based format. Ultimately, this approach will yield the total gravitational force acting on the point mass.