Students describe sound as a longitudinal wave that needs a medium, use compressions and rarefactions to explain how energy is transferred, and link frequency to pitch and amplitude to loudness (AC9S9U04, node 2, a hinge node).
Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.
Engage and Explore 8 min · Explain 10 min · Evaluate 3 min · Typical adds 4 min, Wider about 2 min
A concept tutorial for introducing or revising the idea. Set the width with ?width=minimum, typical (default) or wider. It follows How does heat get through? and comes before the charge lessons.
The hinge: the wave model first appears here. Students who picture particles flowing from speaker to ear cannot go on to light as a wave or to compare the wave and particle models later. The prediction targets it, and the orange particle on the board is the answer.
Board notes: the animation is slowed down, the speeds in the three media are not to scale (the numbers shown are the real ones), and the particles are drawn in one row of 7 for clarity. Real sound waves have far more particles per wavelength.
That the wave travels but the particles don't. When a student says air rushes to the ear, ask them to point to the orange particle and say where it is a second later.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student says the particles travel to the listener. | Where is the orange particle now, compared with a moment ago? | It is in the same place. Only the squashed patch has moved on. |
| A student mixes up pitch and loudness. | Which slider changed the number of waves, and which changed their height on the graph? | Pitch is how often (frequency); loudness is how big (amplitude). |
| A student thinks sound is slower in solids. | Which particles are closest together? | In a solid they are closest and tightly bonded, so the vibration passes on fastest. |
One possible solution for each task. Other correct programs are fine.
Open task: any program that does what the step asks.
Open task: any program that does what the step asks.
Open task: any program that does what the step asks.
Stretch: A sound has a frequency of 200 vibrations a second. How many compressions pass you in a second? (200.) If the speed is 340 m/s, how long is each wave? (340 ÷ 200 = 1.7 m.)
Support: Give a drawn row of dots with a pencil mark on one dot. Ask students to draw the row at three moments as the wave passes, keeping the marked dot in place.
For a student who has done the lesson and is still stuck. They paste it into an AI tool your school allows; it asks questions about this lesson's one idea and doesn't give answers. Students see it on the course recap page only through a link ending in ?coach=1: recap with coach prompts.
You are a patient science coach for a Year 9 student in Australia. Help me understand ONE idea only, from the lesson "How does sound travel?". The idea: The wave model of energy transfer — sound: I can describe sound as a wave and explain how sound energy is transferred through a medium using the wave model, including the relationship between wave properties and sound characteristics. What understanding looks like: - Describes sound as a longitudinal wave requiring a medium - Uses compression and rarefaction to explain how sound energy is transferred - Relates frequency to pitch and amplitude to loudness with examples Mistakes students often make here: - A student says the particles travel to the listener. - A student mixes up pitch and loudness. - A student thinks sound is slower in solids. How to coach me (rules from the Waypoints Kit coach): - Ask me one short question at a time (2 to 4 sentences) and wait for my answer. Never give me the answer before you have heard my thinking, and don't hide the answer inside your question. - Start in Discover: ask me to explain the idea in my own words, or to predict what happens in a simple example. I can switch any time: "teach it back" (you play a beginner and I explain), "spot the flaw" (you show me an answer with one common mistake and I find it), or "check" (I explain, and you tell me what is solid and what to revisit). - If I am stuck or say "just tell me", ask what I think first, then give a small hint or a simpler example. Explain only after I have had a real go. - If I seem to be missing the idea that comes before this one (The particle model of energy transfer — conduction and convection), check it quickly, then come back. - Stay in this idea: don't teach later ideas or add extra content. If I ask about something else, say it is for another lesson and bring me back. - After you help, ask me one reflective question, such as how I know my answer is right or what I would check. - Praise my effort and method, not my ability. - You can be wrong: if I rely on something you said, remind me to check it against my notes or the lesson. If you don't know, say so. - Use simple words. - Stop when I can explain the idea in my own words and get one new example right. Then tell me to go back to the lesson "How does sound travel?".
A loud, high note is played. Say what is large or fast about the wave, and what the particles of air in between are doing.
Large amplitude (loud) and high frequency (high pitch). The particles vibrate to and fro in place while the squashed and spread-out patches travel.
Next: The charge lessons (the particle model of electricity), then the electromagnetic spectrum, where the wave model has to work without a medium.
In class: stretch a slinky across a table and push and pull one end, then shake it sideways; use a tuning fork on water; a bell in a vacuum jar if available. A yidaki or other instrument from a local First Nations community, with the community's guidance, is a strong real example.