Grade level
Developing and using models
Constructing explanations (for science) and designing solutions (for engineering)
Patterns
Cause and Effect
Energy and Matter
PS4.A: Wave Properties
The storyline culminates with students individually drawing new, final models to construct a scientific explanation for the guiding question: "How can your voice break a glass?” The graphic organizer includes a space to draw and label their model, as well as a space to write out an explanation of their model – and, specifically, the relationship between amplitude, frequency, wavelength, and energy.
Immediately before drawing their models, students engaged in a group discussion to develop a “Gotta Have” checklist, identifying the key components to be included in students’ models and/or explanations.
Artifacts A, B, and C share many of the same features, including the primary representation of sounds waves using radiating crescents, the inclusion of microscopic air particles, a recognition that sound waves are caused by – or can cause – materials to vibrate, and fair descriptions of amplitude and frequency.
Even with these commonalities, there are distinct evidentiary claims for why the glass breaks. Artifact A observes that the glass didn’t break at first, and suggests that a louder volume – resulting in more energy being absorbed – was the cause of the breaking glass. Artifact B introduces two terms – “tension” and “resonant frequency” – as key parts of its explanation, suggesting that the frequency of the boys voice caused the glass to “vibrate a lot more”; this artifact’s last sentence might also indicate as evidence that the glass produces or echoes a louder sound the more that it vibrates. Artifact C hypothesizes that the sound waves are reflected within the glass, causing it to vibrate “more violently” due to its material density; the straw’s movement within the glass serves as evidence of the internally reflected vibrations of air inside the glass.
Artifact D mentions several of the same terms as Artifact A-C, including resonant frequency. This artifact demonstrates how sound waves can cause materials to vibrate and accurately explains the relationship between frequency, wavelength, and energy, but offers several – though disconnected – explanations for why the glass breaks.
Artifact E provides a succinct explanation for how two factors – the boy’s specific frequency of sound, called resonant frequency, and a reasonably high amplitude – together caused the glass to vibrate enough to cause its fracture. Note, however, that there is no mention of the mechanical process by which sound waves transfer energy through a medium – in this case, air particles.
Artifacts D, E, and F all differ from Artifacts A, B, and C in that they symbolically represent sound waves differently. Artifact F is interesting, because its representation of the sound wave mirrors a mathematical representation from Chapter 4 of the storyline (from the Sound Grapher exercise).
