properties of waves Flashcards
what is the definition of a longitudinal wave
The vibrations are parallel to the direction of movement
What is the definition of a transverse wave
the vibrations are perpendicular to the direction of movement
what are examples of Transverse waves
Radio
water
EM waves- microwave, gamma waves
what are examples of longitudinal waves
sound waves
Seismic P waves
what is the definition of a Wavefront
points in a wave which oscillate in phase with each other
what is the definition of a wavelength
the distance between two points that oscillate in phase with each other (wavefronts)
What is frequency
The number of waves passing a point per second
What is the time period
the time taken for one complete wave to pass
How do you calculate the wave speed
wave speed= frequency x wavelength
what is the equation for frequency
Frequency = 1/ time period
What is the doppler effect
The apparent change in frequency or in wavelength of a wave for an observer moving relative to its source
what do waves do
they transfer energy and information without transferring matter
what happens to sound when it is coming towards the observer
Wavelength decrease
frequency increase
effect on sound- high pitch
effect of light- more blue
what happens to sound when it is moving away from the observer
wavelength-increases
frequency decreases
Effect on sound- low pitch
effect on light - more red
What happens to sound when there is no relative movement
There is no change to sound, light, wavelength or frequency
state facts about sound waves
sound travels as a wave
they can be refracted
they transfer energy
what can’t sound waves do
Travel through a vacuum
what is the order of the EM waves
Electromagnetic
radio waves
microwaves
infrared rays
visible
ultra violet
x-rays
gamma rays
what do EM waves all have in common
how do they differ?
all transverse
travel through a vacuum
travel at speed
Differ:
wavelength
frequency
what is the function of each EM wave
Radio waves- broadcasting and communication
Microwave- Cooking and satellite
Infrared rays- heaters and night vison equipment
Visible- optical fibres and photography
Ultra violet- Fluorescent lamps
X- rays- observing the internal structure of the objects and material
including medical applications
Gamma rays- Sterilising food and medical equipment
name all the detrimental effects of each EM wave
microwave- internal heating of body tissue
Infrared- skin burns
ultra violet- damaged to surface cells and blindness
Gamma rays- cell mutation, cancer
How is the frequency of the wave linked to energy transferred
the higher the frequency= the more energy transferred
what is the doppler effect
the apparent change in frequency or wavelength of a wave for an observer moving relative to it’s source
