Waves Flashcards
Water waves are _____________ waves
Water waves are transverse waves.
In transverse waves vibrations are _____________ to the direction travel.
In transverse waves vibrations are perpendicular to the direction travel.
Sound waves and waves in a spring are ______________ waves.
Sound waves and waves in a spring are longitudinal waves.
In longitudinal the waves are ________ to the direction of travel.
In longitudinal the waves are parallel to the direction of travel.
The amplitude of a wave is its _________ ___________ from its resting point.
The amplitude of a wave is its maximum distance from its resting point.
The wave length of a wave is the _________ between a point on one wave and the _______ point on the next wave.
The wave length of a wave is the distance between a point on one wave and the same point on the next wave.
The frequency of a wave is the _______ of waves produced by a source each ____________.
The frequency of a wave is the number of waves produced by a source each second.
Wave speed is the __________ travelled by a wave in ___ second
Wave speed is the distance travelled by a wave in 1 second
Time period is the ________ taken to produced ____ wave.
Time period is the time taken to produced 1 wave.
Waves transfer ______ and __________ without transferring matter.
Waves transfer energy and information without transferring matter.
Light is part of a continuous ________________ spectrum which included :
All these waves travel at the same speed in free space
Radio Microwave Infrared Visible light Ultra violet X Ray Gamma ray
Uses of electromagnetic spectrum:
Radio waves
broadcasting
communications
Uses of electromagnetic spectrum:
Microwaves
Cooking
Satellite transmission
Uses of electromagnetic spectrum:
Infrared
Heaters
Night vision equipment
Uses of electromagnetic spectrum:
Visible light
Optical fibres
photography
Uses of electromagnetic spectrum:
Ultra violet
Fluorescent lamps
Uses of electromagnetic spectrum:
X Rays
Observing the internal structure of objects and Material and medical applications
Uses of electromagnetic spectrum:
Gamma rays
Sterilising food and medical equipment
Effects of excessive exposure to the human body :
Microwaves
Internal heating of body tissue
Effects of excessive exposure to the human body :
Infrared
Skin burns
Effects of excessive exposure to the human body :
Ultra violet
Damage to surface cells and blindness
Effects of excessive exposure to the human body :
Gamma rays
Cancer
Mutation
All electro magnetic waves are …
Transverse waves
Electro magnetic waves can all be …
Reflected and refracted
All electromagnetic waves can all travel through a …
Vacuum
Protective measures against the risks :
Suncream
Sun glasses
Avoid
Check microwave doors good seal
The angle of incidence always equal
The angle of incidence always equal angel of reflection
The distance from the object to the mirror is the …
Same distance from the mirror t the image
The image is always the same size as the object but …
Laterally Inverted
When light enters a more optically dence medium …
It slows down. This cause the light to bend or refract.
The amount that the light slows down in the medium is know as the ..
Refractive index
Optical fibres can be used to ________ ___________ using _________ light or _________ radiation
Optical fibres can be used to transmit information using visible light or infrared radiation
Relationship between critical angle and refractive index
SinC = 1
n
For glass critical angle
42
Refractive index
Refractive index = Sin i
Sin r
Frequency range for human hearing is
20 hz - 20000 hz
Wave speed
Wave speed = frequency x wavelength
Frequency
1
Time period
/\/\/ label the wave
Wave length
|
/ \.---- /\
_/\_\_\_\\_\_/_|_\\_\_/
/. \/. \/
AmplitudeUnits Wave speed Wave length Frequency Time
Units Wave speed m/s Wave length m Frequency hz Time s
Light and other types of electromagnetic radiation are ______________ waves.
Light and other types of electromagnetic radiation are transverse waves.
Refraction
causes a change in wave speed and wavelength not frequency
Dispersion
When white light hits an optical boundary at an angle, the different wave lengths are refracted by different amounts and become separated.
The effect of dispersion is best shown in a
Prism where the light hits the 2 boundaries which are at such an angle that the light completely dispersed so the entire spectrum is seen.
Critical angle
A particular angle of incidence of a ray hitting a less dense medium which causes the Ray to be refracted at 90* to the normal
Total internal reflection
This occurs when the angle of incidence of the Ray is greater than the critical angle then the Ray is completely internally reflected
If the angle of incidence is less than the critical angle
The Ray is refracted with a very small reflection
The angle of incidence is equal to the critical angle
Ray emerges along the edge of block
The angle of incidence is greater than the critical angle
The Ray is totally internally reflected
Light rays can be used to transfer
Energy and information along a fibre optic cable very efficiently
Uses of total internal reflection
Periscopes
Reflectors
Optical fibres
Endoscopes
Real image
Formed where light rays cross after reflections by a mirror
Virtual image
Images are formed where light rays only appear to come from
When the light reflects from the surface of a plane mirror the angle is incidence is _______ ___ the angle of reflection
Equal to
Transverse waves
Eg rope, slinky spring, light
Longitudinal waves
Eg slinky spring, sound
Sound waves are
Longitudinal caused y the vibration I’d particle in a solid liquid or gas
Areas where the Particles are close together in a wave are called
Compressions
Human hearing
Lowest audible sound
21
Human hearing
Highest audible sound
20
\ /
\ /
__\/________
\ / reflected wave
\ /
__\/________
Incident wave
Reflection occurs when a
wave bounces from the surface of an obstacle
Reflection best occurs from
Flat, hard surfaces
Properties of electromagnetic waves
- Transfer energy and information from one place to another
- All transverse waves
- Can all be deflected and refracted
- All travel at 300 000 000m/s in a vacuum
