Light Waves & Sound Waves Flashcards
When external radiation bombards certain types of elements, what do the atoms do?
Give examples
Excited atoms give off electromagnetic energy
- often in the form of light
In fluorescent lights argon is stimulated fluoresce
Neon fluoresces when stimulated by electricity
Where can light come from?
Variety of sources:
- Sun
- Light Bulbs
- Excited Atoms
What are waves?
Progressive disturbance
Ex. Water waves / sound waves in the air
propagated from point to point
(with regularity between points)
What is a crest of a wave?
Trough?
Amplitude?
Wavelength?
Crest is the top of a wave
Trough is the bottom of a wave
Amplitude is distance from crest to trough
Wavelength is distance from crest to crest
What is the frequency of a wave?
What can cause higher frequency?
Frequency is how often the crest passes a given point
Higher frequency:
- Speed
- Wavelength (closer - shorter)
What is the Electromagnetic Spectrum?
The waves from the sun
• broad
- Radio-waves - 1 KM
- Infrared (heat) - 1 MM
- Ultraviolet (UV) - 100 NM
- X-ray - 1 NM
- Gamma (radiation) - .01 NM
What is the longest visible color from the spectrum?
Red
What is reflection of light?
Reflection of light occurs when light returns after bouncing off (angle of incidence) an object
What is refraction of light?
Refraction of light occurs when light is bent while passing from one medium
Ex. Solid, liquids, gases
into another
How does matter determine a color?
Whatever color an object DOES NOT absorb will show that color
- white show because it either reflects white or emits all other colors
- black is shown when all colors are absorbed
What are greenhouse gases?
Water vapor
Carbon dioxide
Methane
Warm the earth by trapping heat
- heat (thermal energy) cannot escape
What make sound waves different than light waves?
Sound waves require a medium and travel much slower than light waves
What is the Doppler Effect?
The motion of objects emitting or rejecting sounds waves changes their frequency
The higher the frequency of a sound wave does what to the pitch?
Higher frequency in a sound wave
=
higher pitch
