Types Of Waves Flashcards
How can you use an oscilloscope to measure the speed of sound
Set up the oscilloscope so the detected waves at each microphone are shown as separate waves
Start with both microphones next to the speaker and then slowly move one away UNTILL the 2 waves on the scope line up but are 1 wave length apart
Measure the distance between microphones to find wavelength
Transverse and longitudinal waves
Transverse has vibrations perpendicular to the direction of travel
Longitudinal have vibration parralel to direction of travel
How can you measure the speed of water ripple
Dim lights and turn on the lamp a wave pattern made by the shadows of the wave crests will be made
The distance of each shadows line is equal to a wavelength so measure the whole distance and divide by how many waves there are
If struggling take a photo of the shadows and ruler
How to find waves on strings
Set up equipment shown and turn on the signal generator and vibration transducer the string will start to vibrate
You can adjust the frequency setting on the generator to change the length of the wave created on the string,keep adjusting the frequency UNTILL a clear wave on the string appears ,this will depend upon the length of the string between the transducer and pulley
You can measure the wave length by measure ong all half wave lengths in one go then divide by the total number of half wave lengths to get a mean
Wave transmission reflection and absorption
Waves absorbed by second material ,transfers energy to the materials thermal energy store which leads to heating
Wave transmittion the wave will carry on travelling through material this leads to refraction
The wave is reflected there the incoming wave is sent back
Refraction
When waves cross boundary between 2 materials it changes speed
If hits boundary at angle it will change direction it bends towards normal if slowed down and away from normal if sped up
Ray diagram
Draw boundaries between 2 materials and the normal at a 90* to normal
Draw an indicent ray that meets the normal if given an angle meansure using protractor
Now draw the reflected ray if material is denser the angle is smaller and if less denser the angle is bigger and if the same then it’s the same
Em waves
Travel at same speed trhough air or vacuum
Increasing freqenct and decreases wavelength
How are radiwaves made and used
Their made by ac by the occilating charges they create em waves
Used for communication due to the wave lengths diffracting around the curved surface of the earth
Pros of Bluetooth
You can use several objects at once without the requirement of wires
How are satellites used
Microwaves are used due to them passing through the atmosphere easier
The signal is transmitted into space
Where it’s picked up by the satellite recover dish thousands of kilometres above th Earth
The satellite transmits the signal back to the earth in a differnt direction
Where it’s recived by the dish on the ground
There is a slight time delay between being sent a recived due to the long distance
How can infrared raditation moniter temp
Infrared is given out by all objects the hotter the object the more radiation given out
Infrared cameras are used to detect radiation and moniter temp
The camera detects this and converts it to an electrical system , on the screen the brighter the object is the hotter it is
How can fibre optic cable use visable light to transmit data
Fibre optic wires are think glass or plastic that carry data over long distance as pulses of visible light
This works bc of reflection the rays are bounced back and forth
Florecent lights
Florence is a property of certain chemicals where uv is absorbed and light is emitted
The florentine lights generate uv radiation which is absorbed and remitted as visable light by a layer of phosphor inside the bulb they’re energy efficant
How are X-rays and gamma rays used in medicine
X-rays easily pass through flesh easily but not denser materials like bones
So the amount of radiation absorbed by the image is what gives you the reading
Radiographers used X-rays and gamma rays to treat cancer
High does of these kill all living cells however an over dosabge can kill too many
