Determine the small gravitational force F which the copper sphere exerts on the steel sphere. Both spheres are homogeneous, and the value of r is 65 mm. Express your result as a vector.

acting along the line joining both the sphere and always attractive in nature.

Explanation:

The given radius of both the sphere, r= 65 mm = 0.065 m

So, the volume of the spheres,

The density of steel,

and the density of copper,

Let M be the mass of the copper ball and m  is the mass of the steel ball.

So, kg

kg

The gravitational force, F, between the two objects having masses M and m and separated by distance d is

Where is the universal gravitational constant.

When both the sphere touches each other, d = 2r= 2 x 0.065 = 0.13 m

Hence, the gravitational force between both the sphere,

The nature of gravitational force is always attractive and acting along the line joining the center of both the sphere.