Chapter 4 review Flashcards
What is a wave?
A wave is a disturbance or movement that transfers energy through matter or space, without causing any permanent displacement (change)
What do sound waves do?
Sound waves disturb the air and transfer energy through air.
What do ocean waves do?
Ocean waves disturb water and transfer energy through water.
What is energy?
Energy is the capacity to apply force over a distance.
What is a force?
A force is a push or pull on an object.
What is a crest?
The crest is the highest point of a wave.
What is a trough?
A trough is the lowest point in a wave.
What is equilibrium?
Equilibrium is the rest position.
What is a wavelength?
Wavelength is the distance from crest to crest or the distance to complete one complete trough and one complete crest.
How is wavelength measured?
Wavelength is measured in metres.
What is amplitude?
Amplitude is the height of a wave crest and the depth of a trough.
Where is amplitude measured from?
Amplitude is measured from rest position or equilibrium
What is amplitude related to?
Amplitude is related to the amount of energy in the wave. The larger the amplitude, the greater the energy
What is the relationship between a bright light and dim light and their amplitude?
The amplitude is low for a dim light with low energy, and the amplitude is high for the bright light that has lots of energy.
What is frequency?
Frequency is the number of repetitive motions or oscillations that occur in a given time.
How is frequency measured?
Frequency is measured in hertz (Hz) or cycles per second
what is an inverse relationship?
In an inverse relationship, when one thing increases the other thing decreases.
What happens when the wave length of a wave decreases?
When the wavelength of a wave decreases, its frequency increases.
What is a weird thing about waves that you don’t realize at first?
A wave does not carry water with it, only the energy carried by a water wave moves forward.
What is the matter that energy travels through called?
Matter which energy travels through is called its medium…ie water or air
True/False… energy can travel through solid, liquid, and gas
True, energy can travel through solid, liquid, and gas
What are the two types of waves that travel through a medium?
Transverse waves and Compression waves travel through medium.
What are transverse waves?
Transverse waves the medium moves up and down perpendicular to the direction the energy is traveling. Ie wave going towards the shore, but the boat goes up and down.
What are compression waves?
Sound waves are compression waves, like a coiled spring, where the sound moves back and forth along the same direction
Water waves and earthquake (seismic) waves are what kind of waves?
Earthquake (seismic) and water waves are a combination of transverse and compression waves.
Which waves do not need a medium?
Light waves and radio waves do not need a medium through which to travel.
What is the formula for frequency?
Frequency = Cycles divided by seconds
What is magenta?
Magenta is red plus blue
What is the difference between reflection and refraction?
Refraction is when the light bends and separates. Reflection is when one colour bounces off an item and so you see that colour
Can humans see wavelengths of light that are more than 700 or less than 400?
No, this is the visible spectrum violet is 400 and red is 700.
What is a model?
A model is a way of representing something in order to understand it better.
What does the wave model of light show you?
The wave model of light pictures light traveling as a wave.
What is the simplest way to thing about light?
Visible light is like a wave transferring energy from the sun to the earth or from one place to another
What is light?
Light is a type of wave that can travel through empty space and transfers energy from one place to another.
What is refraction?
Refraction is the bending or change of direction of a wave as it passes through one material to another.
What is white light made of?
White light (sunlight) is made of waves having different wavelengths and frequencies.
What happens when white light is refracted by a prism?
When white light is refracted through a prism, the different wavelengths bend different amounts.
How do longer wavelengths behave differently than shorter wavelengths when refracted?
Longer wavelengths refract less than shorter wavelengths when they are separated by a prism.
How fast does light travel?
Light travels at 300 000 km/s it is the fastest known form of energy
What is the visible spectrum?
The visible spectrum is the range of colours or frequencies of light that are visible to the human eye.
What are the seven most easily seen colours?
Red, orange, yellow, green, blue, indigo, and violet
What is the acronym for the visible spectrum?
ROY G BIV is the acronym for the visible spectrum.
Which colour has the longest wavelength?
Red has the longest wavelength.
Which colour has the shortest wavelength?
Violet has the shortest wavelength.
Which colour has the highest frequency?
Violet has the highest frequency
Which colour has the lowest frequency
Red has the lowest frequency.
Why does a prism or a rain drop create a rainbow effect?
When the light travels through the prism or raindrop, the lightwaves bend at different amounts which splits them into colours.
How did Newton realize that there were colours inside white light?
He refracted light through a prism and saw the colours and realized he had not added any colour to the light, so the colour must already have been there.
What happens if you remove one colour from the spectrum after it has gone through a prism and is going back into another prism?
The light will not recombine into white and will stay in the rainbow… less the one colour. White needs to have all colours.
What is reflection?
Reflection is when light waves strike an object and bounces off. These are the colours that can be seen.
On a red scarf, what colour is being reflected?
Red is being reflected, so you can see it, and the other colours are absorbed.
Why does a red shirt seem black in a dark room?
Since there is no light, there is no red to be reflected off the clothing.
What are primary colours?
Red, Green and Blue are primary colours and these are the three colours you need to make a rainbow.
What are secondary colours?
Secondary colours are those colours that are made when you combine two primary colours:
What is cyan?
Cyan is green plus blue
What is yellow?
Yellow is red plus green
What is magenta?
Magenta is red plus blue
What is the difference between reflection and refraction?
Refraction is when the light bends and separates. Reflection is when one colour bounces off an item and so you see that colour
Can humans see wavelengths of light that are more than 700 or less than 400?
No, this is the visible spectrum violet is 400 and red is 700.
What are you always surrounded by?
You are always surrounded by invisible waves that even pass through you.
What are some of the invisible waves around you?
Microwaves, wireless internet, radio, cellphone waves, suns rays
What is radiant energy?
Radiant energy is energy, such as light, that travels by radiation.
Does the sun only radiate visible light?
No, the sun radiates a broad spectrum of energy, but we only see a tiny band.
How are light waves different than water waves?
In a water wave, water particles vibrate up and down as the wave passes through the water, in a light wave the electrical and magnetic fields vibrate.
What is another name for light?
Another name for light is electromagnetic radiation
What is electromagnetic radiation?
Electromagnetic radiation is the transmission of energy in the form of waves from the longest radio waves to the shortest gamma waves.
Why can you not see radio and infrared waves in the air?
Radio and infrared waves have longer wavelengths and are lower frequency than visible light.
Which waves have the longest wavelength and lowest energy and frequency?
Radio waves have the longest wavelength, lowest energy and frequency
What type of waves are microwaves and radar waves?
Microwaves and radar are types of radio waves.
What is magnetic resonance imaging?
MRI, these are scans of the body that show the insides, such as a brain scan. They can see the energy that is released by the particles in the brain
What are microwaves?
Microwaves have the shortest wavelength and the highest frequency of all radio waves.
How does a microwave work
Microwaves strongly affect water, so it makes the water in food vibrate quickly and heat up. Only food with water can be heated with microwaves.
How do scientists use microwaves in space?
they send microwaves to space to study the composition, motion and structure of distant objects.
What is radar?
Radar is used for tracking movement of automobiles, aircraft, spacecraft etc. Weather forcasting. Anything that can reflect the waves can be tracked.
What is RADARSTAT?
RADARSTAT is a Canadian satellite that sweeps the ground below with radio waves, monitoring ice flow, oil sills, geographical features etc.
What are infrared waves?
Infrared waves are a type of electromagnetic radiation that compared to light has a longer wavelength and lower energy.
What uses infrared in your home?
Your remote control, a CD reader, uses infrared light.
What has more infrared energy?
A warmer item has more infrared energy.
How is infrared used at airports?
They use infrared images to monitor heat from people to make sure arrivals do not have fevers and are bringing illnesses to Canada.
Which wavelengths carry more energy than light?
Wavelengths that are shorter than visible light carry more energy: Ultraviolet, xrays, and gamma rays
Where is ultraviolet found?
Ultraviolet is just beyond the violet spectrum.
What is the difference between ultraviolet light and visible light?
Ultraviolet cannot be seen and it has a shorter wavelength and higher energy and frequency.
How does your body use ultraviolet light?
Your body needs ultraviolet light to create Vitamin D.
What happens if you get too much violet light?
with too much ultraviolet light you will get a sunburn and skin cancer, or damage to your eye surface.
What are some good uses of ultraviolet light?
Ultraviolet light shows fingerprints on crime scenes and can kill bacteria in food
what did Wilhelm Roentgen discover?
Wilhelm Roetgen discovered xray.
How is xray different from ultraviolet light?
Xray has a shorter wavelength and higher energy and frequency than ultraviolet light.
What are some uses of xrays?
Xrays are used to examine luggage at airports, your teeth at the dentist, airplane parts
What are the highest energy and frequency and shortest wavelength waves in the electromagnetic spectrum?
Gamma rays are highest energy and frequency and have the shortest wavelength.
How are gamma rays used?
Gamma rays are used in cancer treatment in focussed radiation spurts.
Where do gamma rays come from
Gamma rays come from nuclear reactions and are produced by the hottest regions of the universe.
