A coin kept inside water `(mu=4//3)` when viewed from air in a vertical direction, appears to be raised by `2*0mm`. Find the depth of the coin in water.

Explanation

To solve the problem of finding the depth of the coin in water, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Information:**
- Refractive index of water, \( \mu = \frac{4}{3} \)
- The apparent shift of the coin when viewed from air is \( 2 \, \text{mm} \).

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