Wave Motion Flashcards
Define waves
Vibrations that transfer energy from place to place without matter (solid, liquid, or gas) being transfered
What waves need mediums to travel through
Sound and seismic waves
What waves do not need mediums to travel through
Visible light rays, microwaves, and other electromagnetic waves
What are the two types of waves
Transverse and Longitudinal
Define transverse waves
Where the oscillations are right angles to the direction of travel and energy transfer
Example of transverse waves
Electromagnetic waves
What is the speed of electromagnetic waves
3x10^8 (speed o light through a vacuum)
Define Longitudinal waves
The oscillations are the same direction as the direction of travel and energy transfer
They show areas of compression and rarefaction
Example of longitudinal waves
Sound waves
Define Amplitude
The maximum height of the wave from its undisturbed central position (from the normal line to the crest) - see image
Define Period
The time taken by a wave to complete one cycle (measured from crest to crest - same as wavelength excepts measures time not distance)
Define wavelength
The distance between a point on the wave and the same point on the next wave (crest to crest or trough to trough)
Define frequency
Number of waves that pass a certain point each second
What is wavelength measured in
Metres
What is frequency measured in
Hz (Hertz)
What is amplitude measured in
Metres
Mechanical Waves
Waves that pass energy through particles through vibrations, particle movement and compression.
State the equation to find wave length
Wavelength = Velocity (speed) divided by frequency
State the equation for frequency
Frequency = Velocity (speed) divided by wavelength
State the equation for velocity (speed)
Velocity (speed) = frequency x wavelength
What are sound waves
A longitudinal wave travelling through material or matter that can be heard.
How does sound move
By molecules moving from where the sound began parallel to the direction of motion
Are sound waves longitudinal or transverse waves
Longitudinal as the vibrations push air molecules back and forth creating longitudinal waves
Define compression
When a sound wave from an object pushes into the air causes the molecules to push together (compress together)
Define rarefaction
When the sound waves pull back from its vibration, the air molecules are furthest apart with low pressure
Define pitch
The frequency of a wave creates a sounds pitch (proportional relationship between pitch and frequency)
What effect does a high frequency have on pitch?
Creates a high pitch
What effect does a low frequency have on pitch?
Creates a low pitch
Define absorption in terms of sound waves
Where sound is absorbed off soft surfaces that don’t reflect
What surfaces does sound absorb into
Soft surfaces that don’t reflect
Define echo
Where sound bounces off hard surfaces
What surfaces does sound echo off
Hard surfaces
