This is a fully self-contained, single-file "Free Physics Doppler Effect Frequency Shift Calculator" web application. It features real-time calculation, responsive design, and a high-performance Canvas-based visualizer. ```html Free Physics Doppler Effect Frequency Shift Calculator

Free Physics Doppler Effect Frequency Shift Calculator

Real-time simulation of wave compression and frequency shift.

Parameters

Observed Frequency

440.00 Hz

Understanding the Visualization

The simulation shows expanding wavefronts. When the source moves towards the observer, the waves are compressed (shorter wavelength = higher frequency). When moving away, waves are stretched (longer wavelength = lower frequency). If source velocity exceeds sound speed, shockwaves (sonic boom) occur.