WAV E S
Miss Emily
Royal IB Jeju
What are waves?
Waves are disturbances that
move energy.
The lights we see and sounds we
here are all products of waves.
Four characteristics
of waves
•
Wavelength: the distance
between two peaks (crests)
•
Amplitude: distance between
the resting position and peak
•
Speed: how quickly the wave
travels
•
Frequency: the number of
waves passing through one
point per unit of time
Frequency (𝑓)
The number of waves passing through one point per unit of
time.
The frequency of the wave is determined by the frequency at
the source of light or sound.
Measured in Hz (hertz), or 1 cycle per second. The human
ear can hear between 20-20,000 Hz.
Inversely related to wavelength (meaning, the longer the
wavelength, the smaller the frequency).
Directly related to (proportional to) energy. The greater the
frequency, the greater the energy of the wave.
Light waves
•
Transverse (particles move perpendicularly
to wave), electromagnetic waves
•
Do NOT require a medium (can travel in a
vacuum)
•
Speed: 3.0 x 108 m/s
•
Light color is determined by the wavelength
(for example, the shortest wavelength (400
nm) is violet, while the longest wavelength
(700 nm) is red)
•
Light intensity – brightness or darkness – is
determined by the amplitude
Sound waves
-
Mechanical & longitudinal (wave particles are
moving in the same direction as the wave)
waves
-
Requires a medium (moves fastest through
solids, then liquids, then gases)
-
-
Speed: 332 m/s
Do not travel as far as light waves
Sound pitch (how high or low the sound is) is
determined by wavelength
-
Sound intensity (how loud the sound is) is
determined by amplitude
Wave
interference
If more than one wave is at work, the waves will
interact. If their peaks/troughs line up, then they
will reinforce each other.
If theirs peaks/troughs oppose one another,
they will cancel out.