Practice question

**Interference of waves** produces enhancement or cancellation based on phase. Two equal amplitude waves out of phase by π cancel completely, A = 0, while in-phase superposition doubles amplitude to 2a, demonstrating energy redistribution without violation of conservation. Destructive interference occurs when two waves of equal frequency are out of phase (e.g., by π radians), resulting in zero net displacement in specific regions. Using v = fλ and standing-wave condition fₙ = n v/(2L) or v/(4L) as applicable, calculation yields Destructive interference, illustrating frequency-length-speed interdependence and quantization by boundaries.