Flashcards
waves for detection or exploration
Flashcards do conjunto (16)
- 1what is special about ultrasonic wavesthey have a frequency greater than 20kHz so they cannot be heard by humans
- 2how are ultrasonic waves partially reflectedwhen an ultrasonic wave meets a boundary between two different media it is partially refracted
- 3how do you determine how far away a boundary isit is possible to determine how far away a boundary is by measuring the time taken for reflected ultrasonic waves to return to a dector
- 4how are ultrasound waves used in industryuses in industry include detecting defects in materials without cutting into them. These defects could be manufacturing faults e.g cracks and air bubbles or damage e.g corrosion
- 5how are ultrasound waves used in medicineuses in medicine include pre-natal scanning, detection of kidney stones and tumours and producing images of damaged ligaments and muscles
- 6what is echo soundingecho sounding, or sonar is the use of ultrasonic waves for detecting objects in deep water or measuring the depth of water
- 7how does echo sounding workit involves sending an ultrasound pulse into the water which is then reflected back when it hits a surface
- 8what is the time between the pulse being sent and the reflection being detected used to calculateits used to calculate the distance travelled by the sound wave:
distance=speed*time - 9what is the speedthe speed is the speed of sound in water (1500m/s). This will find the total distance travelled by the pulse, which is then divided by two to find the depth of the water.
- 10what are the two types of seismic waves produced during an earthquake-p waves (primary)
-s waves (secondary) - 11list the properties of p waves- are longitudinal waves
-travel at the speed of sound and are twice as fast as s- waves
- travel at different speeds through solids and liquids - 12list the properties of s-waves- are transverse waves
-are not able to travel through liquids - 13what can the difference in time between the arrival of p-waves and s-waves at different detectors tell usit can provide evidence about the location of the earthquake and the material they have travelled through
- 14what happens during an earthquake-seismic waves travel outwards from the earthquake and are capable of travelling all the way through the earth
-seismic waves travel in a curved path through the earth, due to the earth increasing in density with depth -
-detectors placed around the earth measure when and where the different waves arrive - 15what is the evidence that comes from the s-wave shadow zone-s-waves are not able to travel through the liquid outer core
-This results in a large shadow zone on the opposite side of the earth to where the earthquake originated
-this shadow zone provides evidence of the size of the earths core - 16what is the evidence that comes from the p-wave shadow zone-p-waves are able to travel through the liquid outer core
-however they are refracted at the boundary between the semi-solid mantle and the liquid outer core
-these refraction's result in p-wave shadow zones
-the study of these shadow zones is used to determine the size and composition of the inner and outer core
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- GCSE physics new FlashCards sobre waves for detection or exploration, criado por ella stokes em 05-11-2017.
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- ella stokes
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