• # Disciplinary Core Ideas

### Physical Science (PS)

Listed below are the Disciplinary Core Ideas (DCI) for Physical Science and bullet points for their specific grade band progression.

#### PS4: Waves and Their Applications in Technologies for Information Transfer

PS4.A: Wave Properties

#### Primary School (K-2)

• Sound can make matter vibrate, and vibrating matter can make sound.

#### Elementary School (3-5)

• Waves, which are regular patterns of motion, can be made in water by disturbing the surface. When waves move across the surface of deep water, the water goes up and down in place; there is no net motion in the direction of the wave except when the water meets a beach.
• Waves of the same type can differ in amplitude (height of the wave) and wavelength (spacing between wave peaks).

#### Middle School (6-8)

• A simple wave has a repeating pattern with a specific wavelength, frequency, and amplitude.
• A sound wave needs a medium through which it is transmitted.

#### High School (9-12)

• The wavelength and frequency of a wave are related to one another by the speed of travel of the wave, which depends on the type of wave and the medium through which it is passing.
• Information can be digitized (e.g., a picture stored as the values of an array of pixels); in this form, it can be stored reliably in computer memory and sent over long distances as a series of wave pulses.
• [From the 3–5 grade band endpoints] Waves can add or cancel one another as they cross, depending on their relative phase (i.e., relative position of peaks and troughs of the waves), but they emerge unaffected by each other. (Boundary: The discussion at this grade level is qualitative only; it can be based on the fact that two different sounds can pass a location in different directions without getting mixed up.)
• Geologists use seismic waves and their reflection at interfaces between layers to probe structures deep in the planet.

This is a table of the Disciplinary Core Ideas of Physical Science. If coming from a Standard the specific bullet point used is highlighted and additional performance Expectations that make use of the Disciplinary Core Idea can be found below the table. To see all Disciplinary Core Ideas, click on the title "Disciplinary Core Ideas."