Study Guide
Longitudinal wave - Answer>> Particle vibration is
parallel to direction of wave propagation
Examples of a longitudinal wave - Answer>> Sound
waves, seismic p-waves
Transverse wave - Answer>> Particle vibration is
perpendicular to direction of wave propagation
Only transverse waves can be polarised
Examples of a transverse wave - Answer>>
Electromagnetic radiation, seismic s-waves
Particle displacement - Answer>> The distance of a
particle from its equilibrium position in given direction
Amplitude - Answer>> The maximum displacement of a
particle (wave) from its equilibrium (or rest) position
Frequency - Answer>> The number of cycles of a wave
that pass a point per second
Time period - Answer>> The time for one complete
oscillation
, Wavelength (for non stationary wave) - Answer>>
Shortest distance between two points in phase
Wavelength for stationary wave - Answer>> Distance
between alternate nodes
or
distance from peak to peak/ trough to trough
Diffraction - Answer>> Spreading out of a wave (when it
passes through a gap or past the edge of an object)
Refraction - Answer>> Wave changes direction when its
speed changes as it crosses a boundary
Polarisation - Answer>> (Transverse) wave oscillation is
in one plane
Application of polarisation in sunglasses - Answer>> •
Light reflected from surfaces is (weakly) polarised in one
plane (horizontal)
• Polaroid in sunglasses can be orientated to remove this
reflected light
• Reducing glare
Application of polarisation in tv transmitters and aerials -
Answer>> • Signals from tv transmitter (radio waves) are
polarised
• Aerials need to be orientated (rotated) so they are in
same plane as the transmitted signal