At what distance along the central perpendicular axis of a uniformly charged plastic disk of radius 0.600 m is the magnitude of the electric field equal to 25% of the magnitude of the field at the center of the surface of the disk ?

Explanation

To solve the problem, we need to find the distance \( x \) along the central perpendicular axis of a uniformly charged plastic disk where the electric field is equal to 25% of the electric field at the center of the disk.

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Radius of the disk, \( R = 0.600 \, \text{m} \)
- Electric field at the center of the disk, \( E_C \)
- We need to find the distance \( x \) where the electric field \( E_x = \frac{1}{4} E_C \).
...