Waves (2) Flashcards
What is wavelength?
The wavelength is the distance between any 2 repeating points in a wave.
What is frequency?
Frequency is the number of waves passing a point in one second.
What is amplitude?
Amplitude is the height of the wave from the middle line.
What is diffraction?
It is when waves bend around an obstacle.
What affects how well the wave diffract?
Their wavelength, as waves with a higher wavelength diffract more and waves with a higher frequency diffract less.
What dictates how loud a sound is?
Amplitude.
How loud is a quiet conversation?
60 decibels.
What is the danger level in terms of sound?
80 decibels.
What range of frequencies can people hear?
20 to 20,000 hertz.
What is ultrasound?
Frequencies above 20,000 hertz.
What can ultrasound be used for?
Creating pictures of babies, finding cracks in pipes, finding fish in the sea and breaking up kidney stones.
What is the Electromagnetic Spectrum?
It is the range or family of waves which travel as transverse waves.
How do transverse waves travel?
Transverse waves vibrate at a right angle in the direction of the wave.
What are some examples of transverse waves?
Radio, water and electromagnetic waves.
How do longitudinal waves travel?
Longitudinal waves vibrate back and forth in the direction of the wave.
What are some examples of longitudinal waves?
Sound, ultrasound and seismic-p waves.
How many decibels can damage your hearing?
110 decibels.
In what case does frequency increase?
Frequency increases going down the electromagnetic spectrum.
In what case does wavelength decrease?
Wavelength decreases going down the electromagnetic spectrum.
The electromagnetic spectrum consists of 8 waves, what are they?
Radio, TV, Microwave, Infra-Red Light, Visible Light, Ultraviolet, X-rays, Gamma Rays. (ALM-332 can be used to remember these, Appliances: Radio, TV, Microwave. Light: Infra-Red, Visible Light, Ultraviolet. Medical: X-rays, Gamma Rays.
What increases as the frequency of a wave increases?
Energy
Why are Radio and TV waves ideal for what they do?
They have long wavelengths meaning they diffract more and are ideal for carrying radio and TV programs.
Who proved that radio can be used for long distance communication (in detail).
Marconi proved that radio can be used to communicate information over a long distance using a radio transmission from Britain to America in 1901. (RADAR)
What can microwaves also be used to carry?
Waves to satellites.
What does RADAR stand for?
RAdio Detection and Ranging.
What is the wavelength range of microwave ovens?
1mm to 50mm.
What is infra red the scientific name for?
Heat.
What can infra red be used for?
Speed up recovery of damaged muscle, drying paint and thermal imaging.
What is visible light made up off?
It is made up of a range of different colours.
When do wavelengths of visible light decrease?
When going along the spectrum (ROYGBIV)
What is a concentrated beam of light called?
Laser.
What can lasers be used to remove?
Birth marks, tattoos and can be used to vaporise tumours.
What can UV light be used to treat?
Acne
What is a security use for UV?
It can be used when paired with fluorescent chemicals that can only be seen using UV light.
What does CAT stand for?
Computer Aided Tomography.
What can X-Rays be used for?
They allow people to investigate the structure of materials down to the arrangement of atoms in crystals.
What ground breaking discovery was made using the X-Ray?
Double Helix.
What can Gamma be used for?
Gamma emitting chemicals can be used as tracers. Gamma emitting chemicals are injected into the bloodstream and can be tracked with a gamma camera.
What can tracers be used to detect except for being injected in the blood?
Can be used to detect cracks in pipes.
What is Radiotherapy?
It is the process of using gamma radiation to damage cancer cells and stop them from reproducing.
What is refraction?
It is the process where the speed of a wave changes as it travels from one medium into another.
What happens when light travels at an angle into the normal from one medium to another?
The direction of the light also changes.
Describe a Convex lens.
Oval shaped, with the light converging on each other when leaving the lens.
Describe a Concave lens.
It is a rectangle shape with two oval half oval cutouts, the light diverges when from each other when leaving the lens.
What is the angle of incidence?
It is the angle at which the light enters a medium.
Why are bones white on a black background when using an X-Ray?
Because X-Rays are absorbed by bone.
