Overview

The focus of this standard is the mechanical wave-like nature of sound and some examples of its application. Sound is introduced in science standard 5.2, and it is expected that standard PS.8 will build upon and expand the concepts of the earlier standard. It is intended that students will actively develop scientific investigation, reasoning, and logic skills, and the nature of science (PS.1) in the context of the key concepts presented in this standard.

 

PS.8           The student will investigate and understand the characteristics of sound waves. Key concepts include

a)     wavelength, frequency, speed, amplitude, rarefaction, and compression;

b)     resonance;

c)     the nature of compression waves; and

d)     technological applications of sound.

 

Essential Understandings

Essential Knowledge, Skills, and Processes

The critical scientific concepts developed in this standard include the following:

  • Sound is produced by vibrations and is a type of mechanical energy. Sound travels in compression waves and at a speed much slower than light. It needs a medium (solid, liquid, or gas) in which to travel. In a compression wave, matter vibrates in the same direction in which the wave travels.
  • All waves exhibit certain characteristics: wavelength, frequency, and amplitude. As wavelength increases, frequency decreases.
  • The speed of sound depends on two things: the medium through which the waves travel and the temperature of the medium.
  • Resonance is the tendency of a system to vibrate at maximum amplitude at certain frequencies.
  • A compression (longitudinal) wave consists of a repeating pattern of compressions and rarefactions. Wavelength is measured as the distance from one compression to the next compression or the distance from one rarefaction to the next rarefaction.
  • Reflection and interference patterns are used in ultrasonic technology, including sonar and medical diagnosis.

 

In order to meet this standard, it is expected that students will

  • determine the relationship between frequency and wavelength.
  • analyze factors that determine the speed of sound through various materials and interpret graphs and charts that display this information.
  • identify examples illustrating resonance (e.g., musical instruments, Tacoma Narrows Bridge, crystal stemware).
  • model a compression (longitudinal) wave and diagram, label, and describe the basic components: wavelength, compression, rarefaction, and frequency.
  • describe technological applications of sound waves and generally how each application functions.
  • design an investigation from a testable question related to sound. The investigation may be a complete experimental design or may focus on systematic observation, description, measurement, and/or data collection and analysis.