Physics 3A Flashcards
x-rays are…
high frequency, short wavelength electromagnetic waves
what do xrays pass through?
healthy tissue
what are xrays absorbed by?
denser materials (bones and metal)
what are CCD’s?
silicon chips the size of a stamp divided up into millions of identical pixels
what do CCD’s do?
detect xrays and can produce electromagnetic signals which are used to form high resolution images
why can xrays be used to treat cancer?
because they cause ionisation, meaning high doses will kill living cells
define ultrasound
sound at a higher frequency than we can hear
what is the human hearing range?
20-20000Hz
what happens to ultrasound waves at a boundary between a media?
they get partially reflected
equation for refractive index
refractive index(n)=sin i(incidence)/sin r(refraction)
