Mechanical vs. Electromagnetic
Waves
Mechanical Waves
• Waves that require a
material medium
• Examples include water,
sound, and waves along a
spring or rope
• These materials carry the
energy of the wave
Electromagnetic Waves
• Waves that DO NOT require a medium for
motion
• Examples include light waves, radio waves,
and X-rays
• All electromagnetic waves travel through
space at the speed of light
• Since these waves can’t be observed, we
study mechanical waves
Electromagnetic Waves
Transverse
Waves
Mechanical
Waves
Longitudinal
Waves
Electromagnetic
Waves
Surface Waves
Waves
Transverse Waves
• Particles of medium vibrate perpendicular to
the direction of the motion of the wave
• Examples include guitar strings, waves in
piano strings
Longitudinal Wave
• Particles of medium to move parallel to the
direction of the wave
• Examples include sound waves, waves through
fluids, liquids, gases or plasma
Surface Waves
• Mixture of transverse
and longitudinal
waves
• Example: At the
surface of the water,
particles move
parallel and
perpendicular to the
direction of the wave.
Earthworm Examination
• Grab an earthworm from the vermicompost.
Study the movement and decide whether an
earthworm moves by longitudinal, transverse,
or surface waves...
Types of Waves
• Using materials around the
classroom, set up a
demonstration showing a:
– Transverse Wave
– Longitudinal Wave
– Surface Wave