A charged particle of mass m and charge q is kept initially at rest on a frictionless surface. Another charged particle of mass 4m and charge 2q starts moving with velocity v towards it. Calculate the distance of the closest approach for both the charged particles.

Explanation

To solve the problem of finding the distance of closest approach between the two charged particles, we can follow these steps:

### Step 1: Understand the System
We have two charged particles:
- Particle 1 (mass = m, charge = q) is initially at rest.
- Particle 2 (mass = 4m, charge = 2q) is moving towards Particle 1 with velocity v.

### Step 2: Apply Conservation of Energy
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