P1 - Radiation and waves Flashcards
(45 cards)
What moves with waves
energy but not particles
What is the amplitude
Gap between centre line and highest point on wave
What is a wavelength
Distance between two crests
What is 1 Hz
1 wave per second
What is the frequencey
Number of wavelengths pass per second
What is the period of the wave
The number of seconds for a wavelength to pass
What direction are the disturbances in transverse waves
90 degrees to the direction
What type of waves are electromagnetic
Transverse
What direction is the disturbances in longitudinal waves
In the direction of the movement
What are some examples of longitudinal waves
Sound waves
Equation for wave speed
Wave speed (m/s) = frequency (Hz) x Wavelength (m)
What to oscilloscopes show
The waveform of a wave
What 3 things can happen when a wave hits a boundary
The wave can be absorbed
Transmitted
or Reflected
What always stays the same in a wave, even if it passes into another medium
the frequency
What is refraction
When a wave hits a different medium, eg. glass, at and angle, and changes direction
What is the order of the electromagnetic spectrum
Radio waves
Microwaves
Infrared waves
Visible light
Ultra violet
X rays
Gamma rays
What happens when high energy waves such as UV, X-rays and Gamma rays
They can ionise the atom
What happens if an electron absorbs an EM wave
It can be excited to a higher radiation level, moving to a higher, partially filled or empty shell
If a high energy wave hits an electron what can happen to it
it can fully leave the atom, ionising it
How do microwaves heat food
They are absorbed into the food, transferring to heat energy
What are some greenhouse gases
CO2, CH4, H2O
What frequency is ultrasound waves
20,000 Hz or above
How does ultrasound imaging work on babies
When the ultrasound leaves the fluid in the womb and enters the babies body, some of it is partially reflected, which can be measured and recorded
What waves to earthquakes produce
Seismic waves
