WAVES-Target 3
Learning target: Understands the relationship between
wavelength, frequency, amplitude, wave velocity and energy.
What is a Wave?
• A vibration or disturbance.
• SOUND & LIGHT are forms of energy that
travel in waves.
Types of Waves
Transverse
• The medium moves at a right angle to the direction of the wave.
• Example: Light
Longitudinal
• A Longitudinal wave is when matter vibrates in the same direction as
the wave travels.
• These are also known as compressional waves.
• The medium moves in the same direction as the wave.
• Example: Sound waves
Parts of a TRANSVERSE Wave
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Crest= High point of a wave.
Trough=Low point of a wave.
Amplitude (A)= Distance from the midpoint to the crest.
Wavelength (λ)= The length of one complete wave.
Parts of a LONGITUDINAL Wave
• Compression: where the wave “squeezes” or compresses the
medium
• Rarefaction: Where there is space in the wave with no
compression.
Wavelength (λ)
The length of one wave is measured from a point on one wave to
that same point on the next wave.
• Crest to crest OR trough to trough
• compression to compression OR rarefaction to rarefaction
• Midpoint (past crest & trough) to midpoint
Frequency (f)
Frequency is the number of occurrences of a repeating event per unit
time.
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# of cycles in one second.
# of waves in one second.
Measured in Hertz (Hz).
1 Hz = 1 cycle per second
If it takes 1 second for the waves to travel the distance shown, what is the frequency?