Count both directions
An echo crosses the distance to the wall twice before returning.
Echo Canyon
Send a visual sound pulse to a wall and measure its roundtrip delay.
Grades 3–5 · Physics
Your goal
At 20 °C, make an echo delay of 200 ms within 5 ms. Send a pulse and step until it returns.
Reduced motion is on. The controls still update the scene.
Sound speed 343 m/s. One-way distance 20.0 m, roundtrip 40.0 m, echo delay 116.6 ms. Send a pulse to begin.
m
°C
Changing distance or temperature prepares a new pulse. This silent model follows a single sound pulse traveling straight to a flat wall and back, using an approximate dry-air speed of 331 plus 0.6 times Celsius temperature in meters per second. It omits wind, absorption and multiple echoes. The pulse stops at the listener when the calculated echo arrives, even if a step passes that instant.
Related resources
Study as flashcards
Related tools
Related worksheets
Related cheat sheets
Related explainers
Learn with Echo Canyon
Echo Canyon lets elementary students investigate the journey behind a reflected sound. Set the wall distance and air temperature, send a visual pulse, and advance the clock in 100 millisecond steps. Follow the pulse outward and back while comparing the one-way distance, roundtrip distance and calculated echo delay. Guided goals ask learners to build a chosen delay and wait for the pulse to return. The silent scene emphasizes that sound covers both directions and that changing air temperature changes the modeled speed of the journey.
What to look for
Watch a pulse
Send a sound pulse and step 100 milliseconds until it reaches the listener again.
Compare temperatures
Warmer air gives a faster modeled sound speed and a shorter delay at the same wall distance.
For teachers and curious learners
Relate echo delay to twice the reflecting-wall distance and sound speed. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
A silent pulse follows one straight out-and-back path. Dry-air speed is approximated by 331 + 0.6T m/s with Celsius temperature. Wind, absorption, diffraction and multiple reflecting surfaces are omitted.