Waves Flashcards
What are the 2 types of waves
Longitudinal and transverse waves
What is amplitude
The maximum displacement a particle can be from its equilibrium position. It is measure in metres
What is Equilibrium position
The position where the particle is undisturbed. This is considered as the halfway point between the two maximum positions of displacement.
What is displacement
The distance a particle is away from its equilibrium position. This can be either positive or negative depending on the side it is on compared to the equilibrium position. Displacement is measured in metres.
What is wavelength
The distance between two consecutive corresponding points on a wave. It is measured in metres.
Symbols of:
Wavelength
Amplitude
Equilibrium position
Displacement
λ
A
E
x
Labels in a longitudinal wave
Compression: an area of high pressure in a longitudinal wave
Rarefaction: region of low pressure
How are wavelengths found in a longitudinal wave
From centre of compression/rarefaction to centre of compression/rarefaction
What do waves do?
Waves transfer energy and information without transferring any mass.
formula to find the speed of a wave
wave speed = distance/ time
Formula to find time period
time period = 1/frequency
what type of waves are EM waves?
transverse
What are the different EM waves from lowest to highest frequency
Radio waves
Micro waves
Infrared
Visible
UV
X-Ray
Gamma ray
What is the wavelength of radio waves
Between 1-100 Km
What is the speed of EM waves?
Speed of light - 3x10^8 m/s
What is the speed of sound?
Around 330 m/s
Who predicted that Radio waves exist and who proved it?
Radio waves were predicted to exist by James Clerk Maxwell and was proven by Heinrich Hertz
Radio waves are the only waves that can do what?
Radio waves are the only waves that can penetrate water at a significant depth, even if it is not much, which is why radio waves are used to communicate with submarines by sending binary signals of waves.
What are radio waves used for and why?
Communicating or sending information of a TV or radio. This is because of the very long wavelength radio waves can diffract and rebound off the ionsphere which other waves cannot do which allows radio waves to better reach some areas in the world.
Wavelength of a microwave
1mm-1m
How does a microwave heat up food?
The frequency of a microwave makes it in such a way that it heats up water molecules. This means that if there is no water in a microwave, nothing will heat up.
What are microwaves most used for?
mobile phones - mobile phones use microwaves to a base station which is used to connect. Microwaves are also used to communicate with satellites in space and for Wi-Fi
Who discovered infrared radiation?
William Herschel in 1800
How are infrared waves emitted?
Anything with heat emits infrared waves. Because of this, infrared cameras work as they can detect the heat signals in different areas and infrared waves are used in heating