Question

Two identical solid copper spheres of radius R are placed in
contact with each other. The gravitational attraction
between them is proportional to​

Answer 1

Answer:

As per the question, the spheres are identical.

So we can consider their masses to be same.

Let the mass of each copper sphere be M.

Now the question says that the spheres are in contact with one another.

So the separation distance is R+R = 2R

Now,

the gravitational force as per Newton's Law

=(GM^2)/{(2R)^2}

=(GM^2)/ 4R^2.

Then see the attached photo, hope you will be able to understand.

Convert the mass to volume* density and then solve the problem.

So the answer is Gravitational force is directly proportional to ( R^4)

Answer 2

$\huge\sf{Answer:-}$

Two identical solid copper spheres of radius R are placed in a contact with each other then the gravitational attraction between them is proportional to R^4

Further Explanation

F = G M1 * M2 / d² = Gravitational attraction between two objects.

Let D be the Distance between mass of two objects.

Hence

= GM² / 2R² = GM² ° R -²

= 2R-² ° R-²

= F = GM² / 4R²

= G (4 / 3 π R³ × P)² / 4R²

= G 16 / 9 π R^6 P / 4R²

= 4 / 9 Gπ P ° R4

= F ~ R4

Therefore , The gravitational attraction between them is proportional to R^4