P6:Waves Flashcards
When waves travel through a medium, the particles of the medium…
Oscillate and transfer energy between each other, but overall, the particles stay in the same place - only energy is transferred
The amplitude is a wave is the maximum…
Displacement of a point in the wave from its undisturbed position
The wavelength is the distance between the same point on…
Two adjacent waves. (EG: between the trough of one wave and the trough of the wave next to it)
Frequency is the number of complex waves passing a…
Certain point per second, frequency is measured in hertz (Hz). 1 Hz is 1 wave per second
From the frequency, you can find the period of a wave using the amount of time it takes for a full cycle of the wave…
T = 1/F Period(s) = 1 / Frequency(Hz)
Transverse waves have sideways vibrations. In transverse waves, the oscillations are perpendicular (at 90*) to the direction of energy transfer.
- All electromagnetic waves
- Ripple and waves in water
- A wave on a string
Longitudinal waves have parallel vibrations…
In longitudinal waves, the oscillations are parallel to the direction of energy transfer. For example, sound waves in the air
The wave speed is the speed at which energy is being transferred or…
The speed the wave is moving at
Wave equation…
V = F x λ Wave speed(m/s) = frequency(Hz) x wavelength(m)
All waves can be…
Absorbed, transmitted or reflected, this occurs when a wave meets a boundary between two materials
The wave is absorbed by the second material…
The wave transfers energy to the materials energy stores. Often, the energy is transferred to a thermal energy store, which leads to heating. For example, a microwave
The wave is transmitted through the second material…
The wave varies in travelling through the new material. This often leads to refraction. This can be used in communications as well as in the lenses of glasses and cameras
The wave is reflected…
This is where the incoming ray is neither absorbed or transmitted but instead it returned away from the second material. This is how echos are created
Whether the wave is absorbed, transmitted or reflected depends on…
The wavelength of the wave and the properties of the materials involved
Electromagnetic waves are…
Transverse waves, they transfer energy from a source to an absorbed
A campfire transfers energy to its surroundings by emitting infrared radiation…
These infrared waves are absorbed by objects and transfer energy to the objects thermal energy store, causing the object to warm up
Radio waves transfers energy to the kinetic energy stores of…
Electrons in radio receivers which generates and electric current
All EM waves travel at the same speed through the air or a vacuum…
EM waves aren’t vibrations of particles, they’re vibrations of electric and magnetic fields. This means they can travel through a vacuum. They travel at different speeds in different materials which can lead to refraction
A vacuum is another name for…
A space
EM waves vary in wavelength from around 10(^-15)…
To more than 10(^4)
We group waves based on their wavelength and frequency…
There are seven basic types, but the different groups merge to form a continuous spectrum
Our eyes can only detect a small part of the electromagnetic spectrum…
Visible light
Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays
Long wavelength, low frequency to short wavelength, high frequency
There is such a larger range of frequencies because EM waves are…
Generated by a variety of changes in atoms and their nuclei. For example, changes in the nucleus of an atom creates gamma rays. Also explaining why atoms can absorb a range of frequencies, each one causes a different change
Because if their different properties…
Different EM waves are used for different purposes
When EM radiation enters living tissue…
It’s often harmless, but it can sometimes creates havoc, the effects of each type of radiation are based on how much energy the wave transfers
Low frequency waves, like radio waves…
Don’t transfer much energy and so mostly pass through soft tissue without being absorbed
High frequency waves like UV, X-rays and gamma rays all transfer…
Lots of energy and so can cause lots of damage