P12 - waves Flashcards
what are the two types of wave and their properties
longitudinal - oscillations are parallel to direction of travel, sound waves, P waves
transverse - oscillations are perpendicular to direction of travel, EM waves, water waves, S waves
what are the 5 properties of a wave and what are they measured in
amplitude - distance from rest point to peak (m)
wavelength - distance between two peaks (m)
time period - time for 1 wave to pass a point (s)
frequency - number of waves per second (Hz)
wave speed - speed the wave travels (m/s)
wave speed formula
wave speed = frequency x wavelength
frequency formula
1/time period
what is reflection called in a sound wave
echo
what is reflection vs refraction
reflection - where a wave bounces off a surface
refraction - when a wave enters a medium of different density so bends
which way does a wave entering a higher density medium refract
towards the normal
what changes when a light wave refracts
frequency stays the same, velocity decreases, wavelength decreases
what areas are there in a longitudinal wave
compression (when the particles are grouped together) and rarefaction (where they are spread apart)
what moves in a wave
energy (not matter)
what is ultrasound and infrasound
ultrasound is above 20000 Hz (20 KHz), infrasound is below 20 Hz
what are the two types of seismic waves and their properties
Primary (P) waves - faster, longitudinal, refract through core
Secondary (S) waves - transverse, can’t travel through liquid outer core causing shadow zones
