Principle of Superposition and Interference

Suppose two waves produce displacements: y₁ and y₂ at the same place and time. According to superposition: y = y₁ + y₂ The waves continue through one another, but while they overlap their displacements combine. Depending on their relative phase, the resulting amplitude can become: larger → constructive interference or smaller → destructive interference Interference is a general wave phenomenon and can occur with: sound waves, water waves, microwaves, and light. Interference does **not create or destroy energy**. It redistributes wave energy between regions of greater and smaller intensity.

**y = y₁+y₂ For two equal-amplitude waves, resultant amplitude: A_R = 2A cos(Δφ/2)**