Question

In this case the resulting wave is __ interference.


constructive


superposed


destructive

Answer 1

I don’t have the diagram or description of “this case,” so I can’t pick one for you. Tell me whether the two waves’ crests line up or crests line up with troughs (or give the phase difference) and I’ll answer.

Quick rules you can use:
- Crest meets crest (phase difference 0, 2π, …) → constructive interference (amplitude adds).
- Crest meets trough (phase difference π, odd multiples of π) → destructive interference (amplitude cancels).
- Any other phase difference → partial interference; the resulting wave is the superposition (sum) of the two waves.

If you want the math: for y1 = A sin(ωt + φ1) and y2 = A sin(ωt + φ2),
ytotal = 2A cos((φ2−φ1)/2) · sin(ωt + (φ1+φ2)/2).
So the resultant amplitude is 2A cos(Δφ/2): zero at Δφ = π (destructive), maximum at Δφ = 0 (constructive).