Waves Flashcards
(28 cards)
Wavelength
Distance from one peak to the next
Frequency
How many complete waves there are per second
Amplitude
Height of the wave
Time period
How long it takes for one complete wave
Transverse
The waves vibrate perpendicular to the direction of energy transfer
Longitudinal
The waves vibrate parallel to the direction of energy transfer
EM waves
-radio waves
-microwaves
-infrared
-visible light
-ultraviolet
-X-Ray
-gamma
(increasing frequency)
Colours of EM
-red
-orange
-yellow
-green
-blue
-indigo
-violet
(Richard of York gave battle in vain)
Waves
Waves are caused by repeated vibrations that transfer energy and information without transferring matter
Radio waves
- communications
- broadcasting
Microwave
- cooking
- satellite transmission
- internal heating of body tissue
Infrared
- heaters
- night vision equipment
- skin burns (prevent with reflective clothing)
Visible light
- optical fibres
- photography
- periscopes
- eye damage
Ultraviolet
- fluorescent lamps
- skin cancer
- blindness
- damage surface cells
X-Ray
- observing internal structure of objects
- cancer
Gamma
- sterilise food and medical equipment
- cancer (lead shielding and wear a film badge)
- kill cells
- tissue damage
TAG
- towards normal
- air
- glass
Human hearing
20-20000Hz
Refraction
When a wave enters a different medium and changes speed/direction
i < c
Refraction and some internal reflection
i = c
Emerging Ray comes out along the surface and some internal reflection
i > c
TIR
Critical angle
The angle when the angle of refraction is 90 degrees
Optical fibres
- central core surrounded by cladding
- light always hits greater than C
