What quantity did you change?
Labs / Physics
Doppler Effect
A sound source glides across the room, ringing out a fresh circular wavefront every fraction of a second. Drag anywhere to fling it in a new direction, or push the speed slider up — the waves squeeze together in front and spread out behind, raising the pitch ahead and lowering it in your wake.
Labs / Physics / Doppler Effect
Doppler Effect
A sound source glides across the room, ringing out a fresh circular wavefront every fraction of a second. Drag anywhere to fling it in a new direction, or push the speed slider up — the waves squeeze together in front and spread out behind, raising the pitch ahead and lowering it in your wake.
Why it matters
Why explore this?
Physics explains how changes in forces, energy, motion, and matter produce results we can measure. This model lets you test one part of that relationship at a time.
Explore
Try the model
v 0.60 Machf ahead 1100 Hzf behind 275 Hz
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Why do the wavefronts pile up in front of the source but fan apart behind it?
- An observer standing dead ahead hears one pitch; someone behind hears another. How far apart are the two frequencies at Mach 0.5?
- Push the speed to exactly Mach 1. What happens to every wavefront right at the nose of the source?
- Go supersonic. Where does the sharp V-shaped shock cone come from, and why does it get narrower the faster you go?
- Let the source bounce off a wall. Does the crowded, high-pitch side switch to the other end the instant it turns around?
Explain
Make sense of what happened
Name the quantity you changed, the quantity that responded, and the physical rule connecting them. Use a readout or visible change as evidence.
Check
Before you leave
What measurable result changed?
Which physical idea connects them?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.