# The World Communicates-Physics

Pages: 2 (275 words) Published: August 23, 2013
8.2 The World Communicates

The wave model can be used to explain how current technologies transfer information. Describe the energy transformations required in one of the following: * Mobile Telephone

Mobile telephones have built in microphones that changes sound waves ib

Describe waves as a transfer of energy disturbance that may occur in one, two or three dimensions, depending on the nature of the wave and the medium

Identify that mechanical waves require a medium for propagation while electromagnetic waves do not

Mechanical: Requires a medium for propagation (ie. Travel through) Eg. Sound Waves, Water Waves, Waves in a string ..

Electromagnetic: Do not require a medium for propagation (ie. EM Waves can pass through a vacuum) Eg. Light, Infrared, UV, X rays, Gamma Rays, Radio waves, Microwaves ..

Define and apply the following terms of the wave model: Medium, displacement, amplitude, period, compression, rarefaction, crest, trough, transverse waves, longitudinal waves, frequency, wavelength & velocity.

Describe the relationship between particle motion and the direction of energy propagation in transverse and longitudinal waves

Quantify the relationship between velocity, frequency and wavelength v=fλ

Where v = velocity, f = frequency & λ = wavelength (lambda)

Features of a wave model can be used to account for the properties of sound. Identify that sound waves are vibrations or oscillations of particles in a medium

Relate compressions and rarefactions of sound waves to the crests and troughs of transverse waves used to represent them

Explain qualitatively that pitch is related to frequency and volume to amplitude of sound waves

Explain an echo as a reflection of a sound wave

Describe the principle of superposition and compare the resulting waves to the original waves in sound