Characteristics of Periodic Waves
Frequency, cycles, pitch, and how repeating waves are measured
What form of energy travels through the auditory nerve?
How the Ear Works
Video Instruction
showmethephysics.com
Review: Frequency, Amplitude & Wavelength
Sound Waves on Film
ERPI Classroom Films · Encyclopedia Britannica · Prelinger Archives · Public domain
School blocks YouTube? Use the onsite MP4.
What is this speaker component called? What kind of waves does it produce—high or low frequency?
Woofer: it outputs low-frequency waves.
II. Characteristics of Periodic Waves
Frequency is determined by the source of a wave—not by the medium.
Cycles
How many cycles are between the dots?
3 cycles
Frequency Example
10 cycles pass a fixed point in 5 seconds. What is the frequency?
Longitudinal or Transverse?
Periodic-Wave Practice
A wave generator operates for 4 seconds and produces the wave train below.
How many waves are drawn between A and B?
What is the frequency of the wave train?
8 cycles
f = 8 cycles ÷ 4 s = 2 Hz
2 cycles pass a fixed point in 10 seconds. What is the frequency?
What Frequency Means
For sound, frequency determines pitch.
For light, frequency determines color.
The Human Hearing Range
20 Hz–20,000 Hz
Dogs can hear higher-pitched sounds than humans. Your own high-frequency hearing range also changes with age—how old do your ears sound?
