Basic Waves 2 Flashcards
(20 cards)
Soundwaves are caused by oscillating particles
in the medium. This causes areas of
compression (——————-) and rarefaction
(——————-). The oscillations of particles
are —————— to the direction of energy transfer.
High pressure, Low pressure, parallel.
Sound can move through —— and ——
but most commonly we look at sound moving
in —-.
Solids, liquids, air
Human hearing can has a frequency range from —- to —- hz.
20 Hz to 20000 Hz
Infra sound is sound with a frequency —— humanhearing
below
Ultrasound is sound with a frequency —- human hearing
above
Examples of Infrasound?
Some animals, such as whales, elephants and giraffes communicate using infrasound over long distances.
Example of Ultrasound?
Some animals, such as bats communicate using ultrasound. We can also use it for medial imaging.
Bats use an —— system. They make high frequency sound —— which last about 3ms. When the sound hits a nearby object, it is reflected back.
echo location, Pulses
It takes time for the sound to reach the object then —— back. The nearer the object the —- time it will take.
reflect, less
The signal must be in —— rather than —— as the time it takes for the echo to return needs to be measured.
pulses, continuous
The pulse must return —— the next one is sent.
before
If it was —— you couldn’t tell when the signal arrived back.
continuous
The —— the pulse the —— the distance that can be measured.
shorter, shorter
Humans use machines to do the same job; for working out —— to objects.
distance
This is especially useful in where?
places where it is hard to see.
By timing how long it takes for the signal to come back we can work out the distance to the object using?
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝑆𝑝𝑒𝑒𝑑 × 𝑡𝑖𝑚𝑒
Sonar can be used —— to measure distance between objects.
underwater
Pulse echo measurements can also be used to ——.
This works because then sound will reflect of any——.
Create an image, Boundary
A computer can build an image from all ———.
the echo measurements
Pulse echos don’t have to be sound.
Radar uses —— waves to detect where planes are in the sky. These travel much —— so the pulses can be shorter and the distances longer.
Radio, faster
