Key Words - waves and the electromagnetic spectrum Flashcards
amplitude
the size of vibrations or the maximum distance a particle moves away for its resting position when a wave passes
electromagnetic waves
a group of waves that all travel at the same speed, in a vacuum, and are all transverse
frequency
the number of vibrations (or the number of waves) per second
hertz
the unit for frequency. one hertz=one waves per second
longitudinal wave
a wave where the particles vibrate in the same direction as the wave is travelling
medium
any substance through which something travels
period
the time taken for one complete wave to pass a point.
seismic waves
vibrations in the rock of the earth caused by earthquakes or explosions
what are the types of seismic waves
there are transverse and longitudinal seismic waves
sound waves
vibrations in the particles of a solid, liquid or gas, which are detected by our ears and heard as sounds
what types of waves are sound waves
sound waves are longitudinal waves
transverse waves
a wave where the vibrations are at right angles to direction the wave is travelling
velocity
the speed of an object in a particular direction.
wave
a way of transferring energy or information
wavelength
the distance between a point on one wave and the same point on the next wave
interface
the boundary between two materials
normal
an imaginary line at right angles to a surface where a ray of light hits it
infrared
electromagnetic radiation that has a longer wavelength than visible light but shorter than microwaves
how are humans effected by infrared
we can feel infrared radiataion as warmth
refraction
the change in direction when a wave goes from one medium to another
ultraviolet
electromagnetic radiation that has a shorter wavelength than light but a longer wavelength than X-rays
visible light
electromagnetic waves that can be detected by the human eye
angle of incidence
the angle between an incoming light ray and the normal
angle of refraction
the angle between the normal and a ray of light that has been refracted
incident ray
a ray of light going towards an interface or object
refracted ray
a ray of light that has just passed through the interface between two materials
electromagnetic spectrum
the entire frequency range of electromagnetic waves
gamma rays
electromagnetic radiation with a longer wavelength than infrared radiation but a shorter wavelength than radio wave
microwaves
electromagnetic radiation with a longer wavelength then infrared radiation but shorter wavelength than radio waves
radio waves
electromagnetic radiation with the longest wavelengths and lowest frequencies
visible spectrum
electromagnetic waves that the human eye can detect
oscillations
movements back and forth. in radios aerials oscillations are repeated changes in voltage and current
fluorescence
absorbing radiation of one wavelength and re-emitting the energy at a different wavelength
radiotherapy
cancer treatment in which a patient is given gamma radiation to kill the cancer cells
DNA
chemical that makes up genes and chromosomes
mutation
a change in the DNA instructions in a cell
skin cancer
a cancer or cancerous tumour on the skin
