Launch two wave sources, map their interference pattern, and locate the nodal lines. Visualize constructive vs destructive interference in real time.
Add two Wave Source objects to the canvas, 4 m apart. Set both to frequency f = 2 Hz and amplitude A = 1. Press Play and observe the wavefronts spreading outward.
Constructive interference occurs where two crests or two troughs meet. These points appear as bright spots in the overlay. Place a probe at one such point and confirm the amplitude is ≈ 2A.
Nodal lines (destructive interference) occur where the path difference equals a half-integer multiple of wavelength: Δd = (n + ½)λ. Move the probe along the canvas to find points where amplitude ≈ 0. Mark them and connect them — these are your nodal lines.
Pick a nodal point and measure its distances d₁ and d₂ to each source using the ruler tool. Confirm that |d₁ − d₂| = (n + ½)λ for some integer n.
Increase the frequency to 4 Hz (halving the wavelength). Count the nodal lines again. The pattern becomes finer — more lines appear as the wavelength shortens.