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Longitudinal waves and the electromagnetic spectrum
Fichas del conjunto (8)
- 1[Longitudinal waves] In a longitudinal wave the vibrations are parallel to the direction of travel of the wave , this kind of wave can be shown or represented by pushing or pulling a string . Sound is an example of a longitudunal wave[Transverse waves]
In a transverse wave the vibrations are at right angles to the direction of travel of the wave . Light , radio and other electromagentic waves are transverse - 2The wavelenght is the distance in metres betweeen two different peakes (or troughs) The frequency in hertz (Hz) is the number of peaks that so past every second The time period is the time taken to completethe cycle of wave motion .The amplitude is the maximum particle displacement in metres in metres of the medium's vibration .
The wave speed is the distance the wave travels in one second , The speed depends on the medium the wave is passing through - 3wave speed = frecuency x wavelenght OR (v = f x λ) where v = wave speed , usually measured in metres/second (m/s) f = frequency , measured in cycles per second or hertz (Hz) λ = wavelenght , usually measured in metres (m)When a wave hits a barrier , the wave is reflected if hits a barrier . if it hits at an angle , then the angle of reflection will be equal to the angle of incidence ,
Echos happen becuas eof the reflection of sound waves . - 4[The electromagnetic spectrum] The electromagnetic spectrum is a 'family' of waves they travel at the same speed through a vacuum .[Gamma rays]
Gamma rays have the shortest wavelenght, therefore they have greatest frequency and energy and they are produced by radioactive substances . They have more energy than X-rays and can cause cancer or mutation in body cells - 5Gamma rays frequently used in radiotherapy to kill cancer cells . The success of this treatment is greatly improved by the fact that cancefr cells are easier to kill than ordainary cellsGamma rays are also used to sterilis emedical equipment , The equipment is place inside a air tight bag , the radiation kills the microrganisms on the equipment and the bag keeps it sterilised until the bag is opened .
- 6[X-rays] They are the next in the electromagnetic spectrum with the highest energy radiation after gammarays . They are produced when high energy electrons are fired at a metal targetBones absorb the X-rays but they are not absorbed by the soft tissue , BUT X-rays have high energy and can damage or destory body cells ; they might ven cause cancer , but they can only be stopped by several centimeters of lead .
- 7[Ultraviolet radiation] is the component from the sun that give you a tan UV is laso created in fluorescent light tubes by exicting atoms in mercury vapour , the UV radiation then is absorbed by the coating on the inside of the fluorescent tube and re-emmited as visible light.Fluorescent tubes are more efficient than than light bulbs becuase they do not depend on heating , so much energy is avabile to create light .
UV can also damage the surface cells of the body which can lead to skin cancer - 8[Radio Waves] Radio Waves have the longest wavelenghts of the electromagnetic spectrum , typically 100 metres . A radio signal is generated by an electrical current , that is inside a metal structure which makes the electrons run up anddown the structure and start generating radio waves .
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- Physics Fichas sobre Sin título, creado por Daniela Del Saz el 25/01/2020.
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- Daniela Del Saz · ene 2020
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- 25 ene 2020
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