IBP I: Introduction to waves
• 4.4.1: Describe a wave pulse and a continuous
progressive (traveling) wave.
• 4.4.2: State that progressive (traveling) waves transfer
energy.
• 4.4.3: Describe and give examples of transverse and
longitudinal waves.
• 4.4.5: Describe the terms crest, trough, compression and
rarefaction.
• 4.4.6: Define the terms displacement, amplitude,
frequency, period, wavelength, wave speed and
intensity.
• 4.4.8: Derive and apply the relationship between wave
speed, wavelength and frequency.
Transfer of energy
• Newtonian via particles
(matter)
• Modern Physics via waves (a
disturbance)
What is a wave?
• “a rhythmic disturbance that
carries energy through matter or
space without net displacement of
the medium.”
• Examples?
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Mechanical vs. Electromagnetic
Waves
• Mechanical waves require a medium
– Speed of the wave determined by the medium
• Electromagnetic waves can travel through
a vacuum
– Describe the EM spectrum
– With what speed to EM waves travel?
• Also dependent upon the medium
Types of waves
• Transverse—medium moves
perpendicular to the direction of wave
travel
– Can’t travel through a fluid—why?
• Longitudinal -- medium moves
parallel to the direction of wave travel
• Surface waves – Characteristics of
both
• Transverse wave:
http://www.ngsir.netfirms.com/englishhtm/
TwaveA.htm
• Longitudinal wave:
http://www.ngsir.netfirms.com/englishhtm/
Lwave.htm
2
What wave Vocabulary
do you know?
• Wavelength (λ, in meters)
• Amplitude (x0, in meters)
• Period (T, in seconds)
• Frequency (f, in Hz (s-1))
3
Wavelength (λ)
• The shortest distance
between the same points
on a continuous wave.
Amplitude (x0)
• Maximum
displacement from
equilibrium
Period (T)
• The time it takes for a wave
to repeat itself (it will equal
the period of the source of
the wave)
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Frequency (Hz)
• The number of complete
oscillations that a wave makes
per second
–examples
• F = 1/T and T = 1/f
Velocity of a
wave
• v=d/t for particles
• v = λ/T or λ(f) for
waves
Frequency depends on the
source, not the medium. It
will not change if a wave
enters a new medium
The speed of a wave
depends on the
medium through
which it travels
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IBP I: Introduction to waves
• 4.4.1: Describe a wave pulse and a continuous
progressive (traveling) wave.
• 4.4.2: State that progressive (traveling) waves transfer
energy.
• 4.4.3: Describe and give examples of transverse and
longitudinal waves.
• 4.4.5: Describe the terms crest, trough, compression and
rarefaction.
• 4.4.6: Define the terms displacement, amplitude,
frequency, period, wavelength, wave speed and
intensity.
• 4.4.8: Derive and apply the relationship between wave
speed, wavelength and frequency.
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