Waves and Electromagnetic Radiation
With Spring Break coming up, some of us will be viewingWAVES up
close and personally! Hopefully all of us will experience an increased
amount of waves from the electromagnetic spectrum.
1. Write down everything you know aboutWAVES in
a KWHL chart.We will discuss this in class.
•Today we are:
• Building an understanding of waves and
common wave terminology
•Introduction to WAVES and electromagnetic radiation
•Definition: A disturbance that transfers energy
from place to place.
•What is it that carries a wave? A medium is the
material through which a wave travels.
•A medium can be a gas, liquid, or solid.
NOT ALL WAVES
REQUIRE A MEDIUMTO
* But most do. The exception would be light from the sun travelling
through empty space.
What causes waves?
•Waves are created when
a source of energy
causes a medium to
•A vibration is a repeated
back and forth or up and
TYPES of waves: Waves are classified
according to how they move.
• Waves that move the medium at
right angles to the direction in
which the waves are traveling is
called a transverse wave.
• Transverse means “across”.The
highest parts are called crests the
lowest parts are called troughs.
• Examples: Ocean waves, Light
•Matter vibrates in the
same direction as the
•Example: Slinky, Sound
•The parts where the
coils are close together
are called compressions,
the parts where the coils
are spread out are called
Basic Properties ofWaves:Terms you will need to know:
•Amplitude is the maximum distance the particles of the
medium carrying the wave move away from their rest
•The farther the medium moves as it vibrates the larger
the amplitude of the resulting waves.The greater the
amplitude the greater the amount of energy
• You can find the amplitude of a transverse
wave by measuring the distance from rest to
crest or rest to trough.
• The amplitude of a compressional wave can
be found by checking the density of the
material in the compressions and
• A wave travels a certain distance
before it starts to repeat. The
distance between two
corresponding parts of a wave is its
• Transverse measure from crest to
crest or trough to trough.
• Compressional wavelengths are
measured from one compression to
•The number of complete waves that pass a given point
in a certain amount of time.
•AKA number of vibrations per second.
•Frequency measured in hertz (Hz).
• The speed, wavelength, and frequency of a wave are related to each other by a
• Speed = wavelength x frequency
• Frequency = speed/wavelength
• Wavelength = speed/frequency
WAVE SPEED EQUATION:
• Waves in different mediums
travel at different speeds.
However, in a given medium
and under the same conditions
the speed of the wave is
• When earthquakes occur, do you think those waves are
compressional or transverse waves? Explain your thinking.