**Category:** Wave Physics

**Subtype:** Interference of Waves

**Problem Description:** This problem involves two coherent sources of waves producing interference on the surface of water. We need to determine the amplitude of oscillation at a specific point (point N) based on the distances from the sources (A and B) and the known amplitude at another point (M). 

**Key Elements:**
- Two sources (A and B) are 25 cm apart, oscillating in phase with a frequency of 25 Hz.
- The wave speed on the water surface is 3 m/s.
- Point M is 15 cm from A and 17 cm from B, with an amplitude of 12 mm.
- Point N is located 2 cm from the midpoint O of segment AB, and we need to find its amplitude of oscillation.

**Objective:** Find the amplitude of oscillation at point N.