A particle of charge q is fixed at point P, and a second particle of mass m and the same charge q is initially held a distance `r_1` from P. The second particle is then released. Determine its momentum magnitude when it is a distance `r_2` from P. Let `q=3.1 mu C. m= 20 mg, r_1 = 0.90 mm, and r_(2) = 1.5 mm.`

Explanation

To solve the problem, we will apply the principle of conservation of energy. The initial potential energy of the system will be equal to the final potential energy plus the kinetic energy of the moving charge.

### Step-by-Step Solution:

1. **Identify Initial and Final States:**
- Initially, the charge \( q \) is at a distance \( r_1 \) from the fixed charge \( Q \) and is at rest, so its initial kinetic energy is zero.
- Finally, the charge \( q \) moves to a distance \( r_2 \) from \( Q \) and has gained some kinetic energy.

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