Physics: Light & The Electromagnetic Spectrum Flashcards
What is wavelength?
The distance from one place in a wave to the next similar place on the wave.
What is the distance from one place in a wave to the next similar place on the wave known as?
Wavelength
What is amplitude?
The wave height from the rest position of the wave to the crest or the rest position to the trough (middle to top or middle to bottom).
What is the wave height from the rest position of the wave to the crest or the rest position to the trough known as?
Amplitude
What is frequency?
The rate of repetition of a wave. Measured in hertz (Hz).
What is the rate of repetition of a wave known as?
Frequency
What is the crest in a wave?
The highest point in a wave.
What is the highest point in a wave known as?
Crest
What is the trough in a wave?
The lowest point in a wave?
What is the lowest point in a wave known as?
Trough
What symbol is used to represent wavelength?
The Greek letter lambda, λ.
What does λ represent?
Wavelength
What is the formula for wave speed?
speed = frequency x wavelength v = f x λ
What is f x λ (frequency x wavelength) the formula for?
Wave Speed
What electromagnetic waves have the longest wavelength?
Radio Waves
What electromagnetic waves carry the news, ball games and music we listen to on the radio?
Radio Waves
What electromagnetic waves are shorter than radio waves?
Microwaves
What electromagnetic waves heat the food we eat?
Microwaves
What electromagnetic waves are used for radar images?
Microwaves
What are the only electromagnetic waves we can see?
Visible Light Waves
What waves can we see as the colours of the rainbow?
Visible Light Waves
What colour has the longest wavelength?
Red
What colour has the shortest wavelength
Violet
What electromagnetic waves have shorter wavelengths than visible light waves.
Ultraviolet Waves
What electromagnetic waves cause sunburns?
Ultraviolet Waves
What electromagnetic waves have smaller wavelengths and more energy than ultraviolet waves?
X-Rays
What electromagnetic waves can easily pass through skin to let doctors look at our bones?
X-Rays
What electromagnetic waves have the smallest wavelength and the most energy of the waves in the electromagnetic spectrum?
Gamma Rays
What electromagnetic waves are generated by radioactive atoms and in nuclear explosions?
Gamma Rays
What electromagnetic waves can kill living cells?
Gamma Rays
What electromagnetic waves can be detected as heat?
Long Infrared Waves (Thermal/Far Infrared Waves)
What electromagnetic waves are given off by the sun and are reflects by plants?
Short Infrared Waves (Near Infrared Waves)
What are hertz (Hz)?
Cycles per Second
What are hertz used to measure?
Wavelength
What is the difference between colours?
Every colour has a different wavelength and frequency.
What does the additive colour theory of light state?
White light is composed of different colours (wavelengths) of light. It is possible to produce white light by combining only three colours.
What are the primary colours of the additive colour theory of light?
Red, green and blue.
What are the secondary colours of the additive colour theory of light?
Magenta, cyan and yellow.
What does the subtractive colour theory of light state?
Coloured matter selectively absorbs different colours or wavelengths of light. The absorbed colours are “subtracted” from the reflected light that is seen by the eye. White objects reflect all colours while black objects absorb all colours. A blue object would reflect blue light and absorb all the rest.
What are the primary colours of the subtractive colour theory of matter?
Magenta, cyan and yellow.
What are the secondary colours of the subtractive colour theory of matter?
Red, green and blue.
What does the subtractive colour theory of matter apply to?
Pigments and the colours they absorb.
