Sound and Optics Test Flashcards
What are musical notes
Rhythmic smooth change in sound waves
What is general noise
Sound waves that vary in frequency without any pattern
What is the range of sound your ears can detect
20-20000 Hz
Sound waves travel through different substances…
at different speeds
What happens when sound waves travel between two substances
The frequency does not change, but the speed of the wave may
Where does the human ear hear best at
3000Hz
What is echo sounding
pulses of high-frequency sound waves to help ships measure water depth
How to work out depth (distance) in echo sounding
1/2 x speed x time
What are sound waves over 20000Hz called?
Ultrasound
What is an ultrasound scanner made up of
A transducer, control system and display screen
What does the transducer do?
Produces and detects sets of ultrasound waves
How do the ultrasound pulses work?
Reflected from the different tissue boundaries in its path
Differences between X-rays
Can be used to scan softer areas, while x-rays usually scan harder parts. Non-ionising
What can ultrasound be used for?
Scanning of humans, industrial imaging
Scanning of the eye
line perpendicular to the mirror
normal line
angle between the incident ray and the normal
angle of incidence
angle between the reflected ray and the normal
angle of reflection
angle of incidence in a plane mirror=
angle of reflection
plane mirror is
virtual
upright
inverted
what is reflection on a smooth surface aka
specular
what is reflection on a rough surface aka
diffuse reflection
when light enters a more dense medium, it is refracted…
towards the normal (angle of reflection is smaller)
when light enters a less dense medium, it is refracted…
away from the normal (angle of a reflection is larger)
the wavelength of colour increases from
Purple to red
how does the colour of a surface change
you can change it by changing the colours of the pigments inside
Translucent objects…
let light pass through but scatters or refracts the light
transparent objects…
let all light that enters it pass through and doesn’t scatter or refract the light
converging lenses make…
parallel rays converge to a focus point, known as the principal focus
diverging lesnses make…
parallel rays diverge; the principal focus is on the ‘left’ side of the lens
the distance from the centre of the lens to the principal focus is called the
focal length
convex lenses form real images when
the object is further away than the principal focus to the lens
convex lenses form virtual images when
the object is closer to the lens than the principal focus
magnification
image height/object height
cameras contain
converging lenses used to form real objects
