In a head on collision between an alpha particle and gold nucleus (Z=79), the distance of closest approach is 39.5 fermi. Calculate the energy of `alpha`-particle.

Explanation

To solve the problem of calculating the energy of the alpha particle in a head-on collision with a gold nucleus, we will follow these steps:

### Step 1: Understand the Concept of Closest Approach
The distance of closest approach in a head-on collision between charged particles is determined by the balance of kinetic and potential energy. At the closest approach, the kinetic energy of the alpha particle is converted into electrostatic potential energy.

### Step 2: Convert the Distance from Fermi to Meters
Given the distance of closest approach \( R_0 = 39.5 \) fermi, we need to convert this into meters:
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