# Wave constructive destructive interference

## Homework Statement

The figure shows two sets of water waves, created by two sources labeled "A" and "B." The solid half-circles represent wave crests from A, and the dashed half-circles represent wave crests from B. Suppose that individual wave crests from either source A or source B alone are 5 mm above the level of the undisturbed water. Then the displacement of the water [above or below the level of the undisturbed water] at the point marked "x" [with the arrow pointing toward it] is

1. +5 mm.
2. -5 mm.
3. +10 mm.
4. 0 mm.
5. -10 mm.

img url: https://ibb.co/ewe8qm

None

## The Attempt at a Solution

Assuming that the two waves interfere at the point I guessed two troughs would interfere and I'd get a displacement of -10, but I'm not quite sure if this is what would occur.