Two identical copper spheres of radius `R` are in contact with each other. If the gravitational attraction between them is `F`, find the relation between `F` and `R`.

Explanation

To find the relation between the gravitational attraction \( F \) between two identical copper spheres and their radius \( R \), we can follow these steps:

### Step 1: Understand the formula for gravitational force
The gravitational force \( F \) between two masses is given by Newton's law of gravitation:
\[ F = \frac{G m_1 m_2}{d^2} \]
where:
...