Waves Flashcards
What do all waves transfer?
Energy.
What is a transverse wave?
In a transverse wave the particles of the medium vibrate at right angles to the direction of the waves energy transfer.
What are some examples of transverse waves?
Light, microwaves, water waves.
What is a longitudinal wave?
In longitudinal waves the particles of the medium vibrate in the same directions as the wave energy transfer.
What is an example of a longitudinal wave?
Sound.
What is the crest of a wave?
The highest point on a wave.
What is the trough of a wave?
The lowest point on a wave.
What is the frequency?
The number of waves that pass a point in one second.
What is frequency measured in?
Hertz (Hz)
What is the period of a wave?
The time for a wave to pass a point.
What is the wavelength?
The distance from one point on a wave to the same point on the next wave.
How do you measure the speed of sound?
- Connect two microphones to a timer
- Measure the distance between the microphones.
- Make a loud sound.
- When the sound gets to microphone 1 the timer starts and when the sound gets to microphone two the timer stops.
- Use d=vt
What is the speed of sound in air?
340 ms-1
What is the speed of light in air?
300,000,000ms-1 or 3x10^8ms-1
What are some examples that show that light is faster than sound?
- Thunder and Lightning
- Fireworks
What is ultrasound?
Sounds with a frequency above 20,000 Hz.
What does the frequency of a sound affect?
The pitch of the sound.
What does the amplitude of a sound affect?
The volume of the sound.
What is diffraction?
Diffraction is the ability of a wave to bend round corners.
How does the wavelength of a wave affect diffraction.
The shorter the wavelength, the less the wave will diffract.
The longer the wavelength, the more the wave will diffract.
What will diffract more, radio or tv waves?
Radio waves as they have a longer wavelength.
What is true about all electromagnetic waves?
- They all transfer energy.
- They are all transverse waves.
- They all travel at 300,000,000 ms-1
- They all diffract.
What is the detector of radio and tv waves?
Aerial.
What is the detector of microwaves?
Aerial.
What are some detectors of infrared?
Photodiode and thermometer.
What are some detectors of visible light?
Photodiode, the human eye and photographic film.
What are some detectors of ultraviolet?
Photodiode or photographic film.
What is a detector of X-rays?
Photographic film.
What are some detectors of gamma rays?
Photographic film and a Geiger - Muller tube.
What is the electromagnetic spectrum in order from longest wavelength to shortest?
Radio waves
Tv waves
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma Rays
What are microwaves used for?
To carry signals up to a satellite in space.
What is infrared used for?
- To speed up the healing of damaged muscle tissue
- Thermal imaging cameras.
What is visible light used for?
- To remove birth marks
- To remove tattoos.
- To kill cancerous tumours.
What is a danger of ultraviolet?
Too much exposure to UV can cause skin cancer.
What are uses of ultraviolet?
- Treating skin conditions like acne
- Security markings
What is a use of X-rays?
To detect broken bones.
What is a use of gamma rays?
To kill cancerous cells.
How does light travel?
In straight lines.
What is refraction?
Refraction of light is what happens when lights passes into a different medium of different density.
What happens when light travels from a less dense medium into a more dense medium?
The light will refract towards the normal.
What happens when lights travels from a more dense medium into a less dense medium?
The light will refract away from the normal.
