Final answer:
The gravitational force exerted by a spherical shell with uniform density on a point mass within its inner radius is zero, according to the shell theorem which is part of Newton's Universal Law of Gravitation.
Step-by-step explanation:
The question is asking for the magnitude of the gravitational force exerted by a point mass on a spherical shell using Newton's Universal Law of Gravitation.
To find the gravitational force, we would usually use the formula F = G(m1*m2)/r^2, where F is the force of gravity, G is the gravitational constant (6.67 × 10^-11 N·m²/kg²), m1 and m2 are the masses of the two objects, and r is the distance between the centers of the two masses.
However, as per the shell theorem, since the point mass is inside the spherical shell and the spherical shell has a uniform density, the net gravitational force exerted by the spherical shell on the point mass would be zero.
It's important to note that in this case, because the point mass is within the radius of the spherical shell, the distribution of the shell's mass has no net gravitational effect on the point mass. Hence, irrespective of the shell's density or the mass of the point particle, the gravitational force exerted on the shell by the point mass is zero when the point mass is inside the spherical shell.