Explain the gravitational force exerted by an extended object.

(N/A) For the gravitational force between an extended object,such as the $Earth$,and a point mass,the equation $F = \frac{G m_1 m_2}{r^2}$ is not directly applicable because it is only valid for point masses.
Each infinitesimal point mass within the extended object exerts a gravitational force on the given point mass. Since these individual forces act in different directions,the total force must be calculated by performing a vector summation of all these infinitesimal forces.
This summation is mathematically represented as an integral over the volume of the extended object: $\vec{F} = \int d\vec{F}$. This process is efficiently handled using calculus.