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81 Cards in this Set
- Front
- Back
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What is a wave? |
A disturbance/movement that transfers energy through matter or space, without causing any permanent displacement
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What is energy? |
The capacity to apply a force over a distance.
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What is a force? |
A push or pull on an object |
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What is rest position? |
The midline between the crest and the trough |
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What is a crest? |
The highest point in a wave
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What is a trough? |
The lowest point in a wave
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What is a wavelength? |
The distance from crest to crest or from trough to trough. Wavelength is measured in metres. |
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What is amplitude? |
The height of a wave crest or depth of a wave trough, as measured from it's rest position |
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How is amplitude related to energy carried by the wave? |
The larger the amplitude, the greater energy transported.
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What is frequency? |
The number of repetitive motions, or oscillations that occur in a given time |
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What is frequency measured in? |
Hertz (Hz), or cycles per second. cycles divided by seconds equals hertz (c/s=Hz) |
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What is an inverse relationship? |
When one value increases as the other decreases (e.g. long wavelengths=less frequency, short wavelengths=more frequency)
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Do water waves carry water? |
No, it carries energy, which makes the water move forward
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What is a medium? |
the matter the waves travel through (e.g. solid, liquid, gas or a combination of these) |
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What happens in a transverse wave? Example? |
Matter in the medium moves up and down perpendicular to the direction that the wave travels. eg. shaking a rope up and down while a friend holds the other end.
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What happens in a compression wave? What is an example? |
Matter in the medium moves back and forth along the same direction the wave travels. Sound waves are compression waves. A slinky. |
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Do all waves need a medium to travel through? If not, what are some examples? |
No, visible light waves and radio waves don't medium. They can travel through space where there is no material.
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How do I calculate Hertz? |
frequency= cycles/seconds e.g. 24 swings in 6 seconds= 4 Hz |
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What is a model? |
it is a way of representing something in order to understand it better and to make predictions. |
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What is the wave model of light? What is light anyway? |
it pictures light travelling as a wave. light is a type of wave that travels through empty space and transfers energy from one place to another (e.g. the Sun to the Earth) |
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What is refraction? |
the bending or changing direction of a wave as it passes from one material to another |
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What is White light? |
It is made up of waves having different wavelengths and frequencies. Sunlight is white light. |
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Why do different colours shoot out from a prism? |
The light is refracted when it passes through a prism. The different wavelengths bend by different amounts. Longer wavelengths are refracted less than shorter wavelengths therefore different colours are separated when they emerge from the prism. |
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Which colour has the shortest wavelength? Which one has the longest? (think of an arched rainbow) |
Red has the longest wavelength (700 nm) and violet has the shortest (400 nm) |
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How did Sir Isaac Newton find out if colour from an object was added to light (as believed at the time), or if the light itself contains colour? |
He placed a prism in a room so a thin beam of white light could pass through it, making bands of colours emerge. Each band was refracted at a different angle. A prism is clear and could not be the source of the colour therefore the colours must have been present already in the white light. |
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What is reflection? |
when a light wave strikes an object and bounces off. Only reflected colours can be seen |
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Why does a red shirt look black if it is placed in a dark room? |
Because it cannot produce it's own light and because there is no light present. It just absorbs whatever colour is around it, which is black.
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The additive primary colours are green, red and blue. What colour is made with: |
red+green make yellow red + blue make magenta blue +green make cyan Also known as the three additive secondary colours |
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what is light classified as? |
an electromagnetic radiation. In a light wave electrical and magnetic fields vibrate. |
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What is electromagnetic radiation? |
the transmission of energy in the form of waves that extend from the longest radio waves to the shortest gamma rays.
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What are radio waves? |
A type of electromagnetic wave that have the longest wavelength and lowest energy and frequency compared to all other types of waves. |
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What are microwaves? |
waves that have the shortest wavelength and highest frequency of all the radio waves. |
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What are Infrared Waves? |
a type of electromagnetic radiation that have a longer wavelength and lower energy and frequency. |
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What are ultraviolet waves? |
a type of electromagnetic radiation that have a shorter wavelength and higher frequency and energy. This energetic radiation allows your skin to make vitamin D (Sun) but overexposure to UV can result in skin damage |
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What are x rays? |
a type of electromagnetic radiation that have a much shorter wavelength and higher energy and frequency than UV waves. Commonly used to photograph bones |
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What are gamma rays? |
a type of electromagnetic spectrum with the highest energy and frequency and shortest wavelength. Used in radiation therapy to kill cancer cells. |
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What two types of waves need a medium to travel through? |
Transverse and Compression
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What is the difference between a crest and a trough? |
A crest is the highest point in a wave and the trough is the lowest point in a wave. |
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What are three way to measure wavelength? |
1) Distance from crest to crest 2) Distance from trough to trough 3) Distance covered by one complete crest plus one complete trough. |
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What property of a wave is measured in hertz (Hz)? |
Frequency |
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How are the wavelength and frequency of a wave related? |
An INVERSE RELATIONSHIP: as one value increases the other decreases |
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What is the difference between a transverse wave and a compression wave? |
Transverse waves: matter in the medium move UP and DOWN - PERPENDICULAR to the direction of the wave Compression waves: matter in the medium move BACK and FORTH along the same direction that the wave travels |
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Can you name two examples of waves that are a combination of transverse and compression waves? |
1) Water waves 2) Seismic waves (earthquake) |
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What could an ultrasound procedure be used for? What type of wave is it? |
Ultrasound waves can be used to make an image of an unborn child. It is a type of sound wave. |
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Name some other uses for sound waves. |
Cleaning lenses and other optical equipment Cleaning dental instruments Cleaning surgical instruments |
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What are the features of a wave? |
- crest - trough - wavelength - amplitude |
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How do noise cancellation headphones work? |
The positive and negative sound waves cancel each other. They have tiny microphones on the outside of the headset that detects the background noise. The wave is analyzed and an exact opposite sound wave that is played back into the headphone. |
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If a female soprano sings at a higher frequency (higher pitch) than a male baritone: Which singer is producing waves of longer wavelength? Explain |
The higher the frequency the shorter the wavelength, therefore the baritone is producing longer wavelengths. |
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If a female soprano sings at a higher frequency (higher pitch) than a male baritone: If both are singing at equal volume which singer is sending more energy out through their voice? Or are they sending out the same energy? |
Volume is way to describe amplitude. Since they both sing at the same volume they produce waves with the same amplitude. The larger the amplitude of a wave the greater the energy transported. The singers are sending out the same energy. |
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What is visible light? (in the simplest terms) |
Visible light is a wave that you can see |
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What is the fastest known form of energy in our universe? |
A light wave travelling through space. The speed of light is approximately 300,000 km/s. That is equal to about seven time the distance around the Earth. |
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What is the visible SPECTRUM? |
The range of colours or frequencies of visible light (red, orange, yellow, green, blue, indigo and violet) ROY G BIV |
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Which colour has the highest frequency? Which colour has the lowest frequency? |
violet has the highest frequency red has the lowest frequency |
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Which colour refracts more in a prism, yellow or blue? |
blue refracts more than yellow because it has a higher frequency than yellow. |
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How does a prism break sunlight up into its component colours? |
It is a solid clear medium that slows down the |
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Contrast refraction and reflection. |
refraction bends light and separates the colours reflection is when an object absorbs all the colours except the one we see because it is reflected back (double check this answer) |
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What is the minimum number of coloured lights needed to produce all the possible colours, including white? |
three |
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List some groups of colours that will work together to produce white light. |
additive primaries- red+green+blue =white additive secondaries - yellow+cyan+magenta=white |
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A certain electromagnetic wave has a wavelength of 200 nm. Is this wave visible to humans? Explain your answer. |
visible light falls between 400 and 700 nanometres (nano means billionths, 9 zeros) The wavelength of 200 nm is not visible to humans. It is above the range of visible light. Remember the shorter the wave the higher the frequency. 200 nm is closer to ultraviolet light |
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A micrometre (um) is one millionth of a metre. State the wavelength of the wave: a) in micrometres b) in millimetres c) in metres |
to figure what one millionth (10 to the power of negative 6) looks like: - write 1 million backwards: 000 000 1 - put the decimal after the first zero and adjust the spacing: 0.000 001 (still 6 zeros as in millions) a) 1 micrometre = 1 micrometre b) 1 micrometre = 0.001 millimetres c) 1 micrometre = 0.000 001 metres micro means one millionth, milli means one thousandth
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Suppose that a device is built that converts colour into sound. For example, if this device detects the colour yellow, it will produce the tone equivalent to middle C on the piano. If it detects blue, then it will produce the same tone one octave higher in pitch (C above middle C) How will the sound for red light compare with the two tones mentioned above? |
you can look this up on the internet or just guess if the order for colour is red, orange, yellow, green, blue, indigo, violet and the musical notes are middle c,d,e,f,g,a,b , above middle c,d,e,f,g,a,b, same distance between red and yellow as yellow and blue. red would be below middle C. ??? |
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Suppose that a device is built that converts colour into sound. For example, if this device detects the colour yellow, it will produce the tone equivalent to middle C on the piano. If it detects blue, then it will produce the same tone one octave higher in pitch (C above middle C) How will green, orange, and violet compare to the two tones mentioned above? |
try to think this one though using the same logic as the last 'pitch question' Orange would be below middle C green and violet would be just below C above middle C and just after C above middle C respectively |
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Where does visible light fall on the Electromagnetic Spectrum? |
It comes after radio waves and infrared radiation (which both have longer wavelengths, lower frequencies and less energy) and before ultraviolet light, X rays and gamma rays (which all have shorter wavelengths, higher frequencies and more energy.
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What are three wavelengths that are shorter than visible light? |
Ultraviolet waves, x rays, gamma rays Ultraviolet is the longest wave (and closest to visible light) of the three, gamma is the shortest |
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What wavelengths are longer than visible light? |
Radio waves, microwaves, infrared waves Rado waves are the longest wave of the three, infrared waves are the shortest and closest to visible light. |
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Where is visible light found on the electromagnetic spectrum? |
between infrared waves and ultraviolet waves wavelengths between 400- 700 nanometres (nm) higher frequency than infrared but lower frequency than ultraviolet waves |
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Which type of electromagnetic radiation has the longest wavelength? |
Radio waves |
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Why does an empty plate not heat up in the microwave? |
Only foods that contain water particles can be heated using microwaves. Microwave ovens use a specific wavelength that is strongly absorbed by water. |
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What are some different uses for radio waves? |
Radio and television broadcasting Microwave ovens Radar detection Magnetic resonance imaging (MRI) |
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What are some other used for microwave frequencies? |
-telecommunications satellites -scientists use radio waves to learn more about the composition, motion, and structure of distant objects. |
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What is the order of waves from the longest (lowest frequency) to the shortest (highest frequency) on the Electromagnetic wave spectrum? |
R M I V U X G (Red Makeup Infuriates Very Ugly X Girlfriends) Radio, Micro, Infrared, Visible, Ultraviolet, X ray, Gamma |
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What are some uses for Infrared waves? |
-TV remote control -Read CD-Roms -heat radiation (heat lamps to warm food) -used at some airports to determine if passengers have a fever -to observe forests and crops to monitor damage from insects, fire, disease |
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What are two uses of radar? |
-track automobiles and aircraft -weather forecasting |
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What is another term for heat radiation? |
Infrared radiation |
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What does Infrared mean? |
below red |
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What does Ultraviolet mean? |
above violet |
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What are three uses/benefits of Ultraviolet waves? |
-UV rays that touch our skin enables the body to make vitamin D (too much will cause damage) -fluorescent materials absorb UV waves and emit energy as visible light (detectives use this to find fingerprints) -UV waves kill bacteria in food, water and medical supplies |
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What are uses for X ray waves? Name three. |
-low doses used to form images of internal organs, bones and teeth -examine contents of luggage -used to photograph inside machines and inspect for cracks inside high performance jet engines |
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What can gamma rays be used for? |
Focussed bursts are used in radiation therapy to kill cancer cells. |
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Where are Gamma Rays produced? |
The hottest regions of the universe. They result from nuclear reactions. |
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What can result from overexposure to ultraviolet waves? |
Sunburns and skin cancers, and damage to the surface of the eye. |
