P6 - Waves Flashcards
What are transverse waves
The vibrations are perpendicular ( at right angles ) to the direction of energy transfer
What are longitudinal waves
Vibrations are in the same direction as the energy transfer
Example of longitudinal wave
Sound wave
Example of transverse wave
Light , waves on a string
What is the amplitude
Maximum displacement of a point on the wave from its undisturbed position
What is wavelength
Distsnce between one point of the wave and the same point on the next one
What is the frequency
Number of complete waves passing a certain point per second
What is period
Period is the amount of time it takes for one complete wave to pass a certain point
How do you find out wave speed
Frequency x wavelength
What is the wave speed
Speed at which energy is being transferred through the medium
What is a refraction
When a wave crosses a boundary between two materials it can change direction
When are waves refracted
Only if they meet the boundary at an angle
What are rays
Rays are straight lines that show the direction a wave ia travelling in
What type of waves are EM
transverse waves
What do electromagnetic waves do
Transfer energy from a source to an absorber
Example of campfire -electromagnetic wave
A camp fire is a source.
It transfers energy to its surroundings by giving out infrared radiation.
Infrared radiation is a type of EM wave.
Infrared waves are absorbed by objects
Continous spectrum of EM waves low to high frequency
Radio waves
Micro waves
Infra red
Visible light
Ultra violet
X rays
Gamma rays
If an EM wave has a high frequency it has a
Short wavelength
What are radio waves used for
Radio and TV signals can be sent by radio waves
Very short wavelength used for radio and TV
Longer wavelength radio waves travel further - used to send signala around the world
What are microwaves used for
Communication with satellites uses microwaves e.g. for satellite TV and satellite phones
Microwave ovens use microwaves to cook food
What is infrared radiation
Infrared cameras detect IR radiation and create a picture.Useful for when seeing where ahouse is loaing energy.
Infrared radiation also used to heat things up.Electric heaters release lots of IR radiation to warm a room
What is visible light used for
Optical fibres are thin or plastic tubes that can carry data over long distsnces.Information sent as light rays
How are x tays and gamma rays used
X rays pass easily through flesh but not through bones.Can be used to make an X ray image to check for broken bones
Gamma rays used to kill cells, can be sued to treat cancer
What is an oscilloscope
Measure the speed of the sound
