Waves Flashcards
What do waves transfer?
waves transfer energy without transferring matter
What is displacement in a wave?
distance from rest position (of a particle)
What is amplitude?
measurement of distance between oscillation position and furthest wave point
What is wavelength?
distance between successive crests or successive troughs
Define ‘wavelength’ in terms of particles.
distance between successive particles moving in phase
What are some examples of transverse waves?
water
all electromagnetic radiation
seismic S-waves (secondary)
What is time period T?
time for one complete oscillation of a particle
What is frequency?
number of oscillations per second
Formula for wave speed.
frequency x wavelength
What is the direction of vibration in a transverse wave?
perpendicular (right angle) to the direction of propagation
What is the direction of vibration in a longitudinal wave?
parallel to the direction of propagation
What are some examples of longitudinal waves?
sound waves
seismic P-waves (primary)
What causes wave refraction?
change of speed
What is refraction?
change in wave speed that results in a change of wave direction
What causes wave diffraction?
when waves go through a narrow gap or meet an obstacle
What causes LITTLE diffraction?
when the gap size is bigger than the wavelength
What causes A LOT of diffraction?
when the gap size is a similar size to the wavelength
What is diffraction?
the spreading out of waves through a gap or around an obstacle
How does wavelength affect diffraction at an edge/obstacle?
the bigger the wavelength, the more diffraction
when wavelength is small there is no diffraction (eg microwaves)
What happens when water waves go from deep to shallow water?
when they enter shallow water at an angle, they slow down an change direction
What happens to the frequency of the wave when it slows down?
does not change
What happens to the wavelength of the wave when it slows down?
wavelength decreases
what moves waves forward
transfer of kinetic energy
transverse waves
oscillation is perpendicular to direction of energy transfer (propagation)
