Waves Definitions Flashcards
Frequency
the number of waves passing any point per second
Period
the time for one oscillation
Wavelength
the distance between any point on a wave and the equivalent point on the next
Amplitude
the maximum distance a point moves from its rest position when a wave passes
Ultrasound
sound with a frequency of higher than 20kHz(above the range of human hearing)
Compression
a region in a longitudinal wave with a higher than normal pressure(particles are closer together)
Rarefaction
a region in a longitudinal wave with a lower than normal pressure(particles are further apart)
Echo
a reflection of sound waves
Luminous
capable of emitting their own light
Non-luminous
incapable of emitting their own light
Diffuse reflection
the reflection of light from an uneven surface such that an incident ray is reflected at many angles rather than just one
Regular reflection
the reflection of light from a smooth surface such that an incident ray is reflected entirely within the same angle
Monochromatic
referring to light of a single frequency, wavelength and colour
Angle of incidence
the angle between the incident ray and the normal
Angle of refraction
the angle between the refracted ray and the normal
Real image
an image formed when rays from a source focus(meet) to form it
Virtual image
an image formed by the imaginary intersection of light rays
Angle of refraction
the angle between the refracted ray and the normal
Refractive index
the ratio of speeds of a wave in two different regions
Dispersion
the separation of white light into colours according to wavelength
Critical angle
the angle of incidence beyond which total reflection occurs
Principal focus
the point where rays converge(meet)
Focal length
the distance from the centre of the lens to the principal focus
Principal axis
a line which passes through the centre of the lens
