27 terms

# Hug- Waves, PH-CIA Chapter 17 and 18.

Waves
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wave
disturbance that transfers energy from one place to another. Come in either transverse (top) or longitudinal (bottom)
medium
any substance that a wave moves through. A form of matter that a wave moves through, including a solid, liquid or gas.
mechanical wave
wave that transfers energy through a medium ( which is a state of matter like solid, liquid and gas)
transverse wave
the wave travels in a direction that is at right angles to the direction of the disturbance
longitudinal (compressional) wave
a wave that travels parallel to the matter it is disturbing and which has areas of compression and rarefaction.
trough
lowest part of a wave
amplitude of a transverse wave
distance from the middle or rest point of the wave to the crest or from the middle to the trough (Part B)
wavelength
The distance from one wave crest to the next or one wave trough to the next. (Part D)
frequency
number of waves that pass a fixed point in a certain amount of time
measured in hertz (hz) which is waves per second
wave speed formula
wavelength x frequency
reflection
bouncing back of a wave after it strikes a barrier
refraction
bending of a wave as it enters a new medium at an angle other than 90 degrees
diffraction
spreading out of waves through an opening or around the edge of an obstacle
interference
the meeting and combining of waves. Constructive interference increases amplitude, destructive decreases amplitude.
crest
the highest point of a wave
opaque
reflecting or absorbing all the light that strikes it.
transparent
allowing light to pass through easily without scattering
translucent
permitting some light to pass through with scattering
focal point
the point where an image forms clearly when light is reflected or refracted by a mirror or lens.
convex
a mirror or lens that is curving or bulging outward.
concave
a mirror or lens that is curving inward.
electromagnetic spectrum
All of the frequencies or wavelengths of electromagnetic radiation from long period radio to short period gamma waves. Electromagnetic waves can travel through space and do not need a medium. All EM waves travel at the speed of light.
EM waves from low to high frequency
radio, microwave, infrared, visible light, ultra-violet, xrays, gamma rays.
Primary colors of light
red, blue and green
High to Low Frequency EM waves
Gamma, X-ray, Ultraviolet, light, infrared, microwave, radio
uses and dangers of em waves
gamma rays - to kill cancer cells -mutations and cell damage
x-rays - see bones, security, telescope - cell damage, cancer
ultra violet light - detect forgeries, sterilize - skin cancer, eye damage
infrared - remote controls, thermal imaging - overheating
dopper effect
the apparent change in the frequency of a sound caused by the motion of either the listener or the source of the sound