Waves Lab

Everywhere

• Topic tabs (under the title) switch between simulations in this lab. Some topics have smaller buttons under the stage for their screens.
• Teach shows live equations with the current numbers and "What to notice" points. Practice gives a numeric problem and a quiz.
• Move the sliders or tap the chips in the right-hand panel. The readings box updates live.
• Pause / Restart control the animation. Clean view hides everything except the stage, for projecting or recording; press Esc to leave it.
• In Practice, type a number (e.g. 12.5 or 3.2e-10), press Check or Enter. Show it on the stage sets the simulation to that problem.
• Nothing is saved: scores reset when the page is reloaded.

Language

• Choose English or বাংলা once on the home page (top right); every lab then opens in that language — tabs, controls, readings, equations, notes, problems and quizzes.

Progressive waves

• Transverse wave: a travelling wave with one particle marked in red — it only moves up and down while the shape moves along. λ, f and A are sliders; the particle's own motion is traced against time.
• Longitudinal wave: rows of particles shuttling back and forth to make compressions and rarefactions, with the displacement graph underneath.
• Wave equation & phase: two points on the wave, their path difference and phase difference 2πΔx/λ, and their motions against time.

Superposition & stationary waves

• Superposition: two waves and their sum, with the phase difference and the second amplitude adjustable.
• String fixed at both ends: harmonics 1 to 6 with nodes and antinodes marked, f = nv/2L.
• Pipes: closed or open, the displacement envelope, and the list of allowed harmonics with their frequencies.

Beats

• Two close frequencies, their sum inside its envelope, and the beat frequency |f₁ − f₂|.

Doppler effect

• Moving source & observer: wavefronts spreading from a source that may move, an observer that may move, and the heard frequency.
• The four cases: all four formulas evaluated side by side.

Speed & intensity of sound

• Speed of sound: v = √(γRT/M) against temperature for air, helium, CO₂ and hydrogen, with Newton's and Laplace's values.
• Intensity & decibels: I = P/4πr² and L = 10 log(I/I₀) on a decibel ruler from a whisper to a jet engine.

Full guide with teaching tips: User manual (also as a PDF).