Flashcards
Section 3- Waves
Flashcards do conjunto (27)
- 1What do all waves have?Wavelength, Amplitude, Frequency and Speed.
Wavelength= the distance from one peak to the next
Frequency= is how many complete waves there are per second.
Amplitute= Height of the wave (from rest to crest)
Speed= is how fast you go (velocity)
Period= time it takes for one complete waves. - 2Whats the equation linking Wave Speed, Frequency and wavelength?Speed=Frequency x wavelength
or - 3What is a transverse wave?the vibration are at 90 degrees to the direction energy is transferred by the wave.
1) Light
2) A slinky spring wiggled up and down
3) Waves on string
4) Ripples on water. - 4What is a longitudinal wave?In longitudinal waves the vibrations are along the same direction as the wave transfers energy.
1) sound and ultrasound
2) Shock waves - 5What do all waves transfer?energy and information without transferring matter.
- 6What can all waves be?Reflected- waves rebound off, Refracted-which means they go through the new material but change direction and Diffracted.
- 7What are the seven types of Electromagnetic (EM) Waves?Radio Waves
Microwaves
Infrared
Visible light
Ultra Violet
X-Rays
Gamma Rays - 8What are all types of EM radiation?Transverse waves and travel at the same speed through free space.
- 9What does the colour of the visible light depend on?Wavelength.
- 10What are Radio Waves used for?Communications/
2) Long-wave radio diffract around the curved surface of the Earth. So can be received from half way around the world.
3) The radio waves used for TV and FM radio broadcasting have very short wavelengths.
4) Short Wave radio signals can be received from long distances. This is because they are reflected from the ionosphere an electrically charged layer in the earths upper atmosphere. Medium- wave signals can also reflect from the ionosphere depending on atmospheric conditions and the time of day. - 11What are microwaves used for?1) They have shorter wave lengths compared to radio waves
2) satellite communication uses microwaves
3) For satellite TV the signal from a transmitter is transmitted into space. and is picked up by an orbiting dish. It is then transmitted back to earth. - 12What are microwaves in ovens absorbed by?Water molecules.
- 13What is infrared radiation used for?heating and to motor temp.
1) infrared is heat radiation
2) IR is given out by all objects - 14What can light signals travel through?optical fibres.
1. Visible light can be used for communication, using optical fibres. Why carry data over long distances as pulses of light. - 15How do optical fibres work?Bouncing waves off the sides of a very narrow core. The pulse of light enters the fibre at a certain angle at one end and is reflected again and again until it emerges at the other end.
- 16What do optical fibres do in terms of using them for medical purposes?They see inside the body without having to operate.
- 17What is visible light also used for?Photography.
- Aperture
-shutter speed
-control light - 18What is UV light used in?Fluorescent lamps.
- 19What do X-Rays do?Let us see inside things.
-internal structure
- diagnose brocken bones
-exposing to X-rays can cause mutations which can lead to cancer. - 20What can gamma rays be used for?Sterilising medical equipment
-kills microbes
Sterilising food
- killing microbes
-food fresh for longer
-not radioactive afterwards so can keep perfectly safe. - 21What are the dangers of electromagnetic waves?Some EM radiation can be harmful
-enters living tissue, sometimes it will be absorbed. e.g. microwaves
can cause cancerous changes. - 22What makes EM even more dangerous?High Frequency, e.g. in X-rays
Order of increasing frequency:
Microwaves-Heat human body tissue
Infrared- cause skin burns
UltraViolet- ionising can cause mutations
Gamma- Tissue damage or cancer - 23What does reflection of light let us do?See things.
- 24What wave is visible light and em light?Transverse
- 25What does reflection of light help us do?allows us to see most object. Light bounces off them into our eyes.
- 26What is the law of reflection?Angle of INCIDENCE = Angle of REFLECTION
- 27How do you draw a ray diagram?1) The image is the same size as the object.
2) It is as far behind the mirror as the object is in front
3) Its formed from diverging rays which means its a virtual image.
picture- P36
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- Physics and Chemistry (Physics) FlashCards sobre Section 3- Waves, criado por marniearose em 03-06-2015.
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