Video

St. Mary's Physics Online

This movie is part of the collection: Prelinger Archives

Production Company: ERPI Classroom Films, Inc. Distributed by Encyclopedia Britannica
Audio/Visual: sound, B&W

What is this speaker component called?

What kinds of waves does it produce?

High or low frequency?

Woofer, Outputs low frequency waves

II. Characteristics of Periodic Waves

A. Frequency(f) = #vibrations/sec

= # Cycles/# sec

= Hertz (Hz)

Source: Elroy M. Avery School Physics
(New York: Sheldon and Company, 1895) 202

Clipart ETC

Heinrich Hertz was the first to send

Frequency

- Determined by

Source
of Wave,

Not Medium

Cycle = (single vibration)

Ex)

How many cycles between the dots?

3 Cycles

 Ex) 10 cycles pass a fixed point in a wave train in 5 seconds. What is the frequency of the wave?

 f = 10 cycles = 2 cycles 5 seconds 1 sec

f = 2 Hertz (Hz)

Top View of a Wave

[ HTML5 ]
St. Mary's Physics Online

Sound Waves
David Kirby - U. of Calif.

Top view of a periodic wave
(Each line is a crest)

Crest
Physics 2000

Review - Longitudinal or Transverse?

[ Flash ]

Ex) A wave generator operating for
4 seconds
produces the waves drawn below.

Top view of a periodic wave
(Each line is a crest)

How many waves are drawn between A and B? (Be careful!!)

What is the frequency of this
periodic wave train?

8 cycles

f = 8 cycles/4 sec

f = 2 cycles/sec

 Ex) 2 cycles pass a fixed point in a wave train in 10 sec. What is the frequency ?

f = # Cycles/# sec

f = 2 Cycles/10 sec

f = .2 Hz

• Sound, frequency is pitch.

Source: Elroy M. Avery School Physics
(New York: Sheldon and Company, 1895) 247

• Light, frequency is color.

Human Ear:

Frequency Range

20 Hz - 20,000 Hz.

 Did you know dogs are capable of hearing higher pitch sounds than humans?

The range of frequencies you
can hear changes with age.

How old are you?

;

How to get rid of teenagers

2006 McGraw-Hill Higher Education

Enrichment

How the Ear Works

Producer: Bosse (Karl Kurt)
Audio/Visual: Sd, B&W
Keywords:

How Sound Works

Sound of a bell in a vacuum