P1.5 Different waves Flashcards
In a transverse wave how does the energy travel?
Perpendicular
In a longitudinal wave how does the energy travel?
Parallel
What is the electromagnet spectrum starting with lowest energy and frequency and longest wavelength at the top
- Radio waves
- Microwaves
- Infrared
- Visible light
- Ultraviolet
- X-rays
- Gamma radiation
Give an example of each waves
Radio waves = television signals Microwaves = cooking mobile phones Infrared = optical fibre communication Visible light = seeing Ultraviolet = detecting forged bank notes X-rays = medical images of bones Gamma radiation = killing cancer cells
Give an example of transverse waves
Electromagnet radiation
Give an example of longitudinal waves
Sound waves
Longitudinal waves show areas of what?
Compression (close together)
Rarefaction (further apart)
What is diffraction?
The effect of waves spreading out when passing through a gap or passing by a barrier where the waves would go around the corners
What happens during refraction when the ray enters medium that is more dense?
The ray bends towards the normal
What happens during refraction when the ray enters a medium that is less dense?
The ray bends away from the normal
Define frequency, wavelength and amplitude
Frequency = number of complete cycles per second
wavelength = distance of one complete cycle
amplitude = distance from top of crest to bottom of trough
What is the equation for finding out speed in metres per second?
v = f x λ
What does v, f and λ mean?
v = speed in metres per second f = frequency in hertz per second λ = wavelength in metres
What is the angle of incidence equal to?
The angle of reflection
What is the normal line?
The line that is perpendicular (90 degrees) to the medium
When an object moves away from an observer what is its light affected by?
The Doppler effect
How do we know our sun contains helium?
Because there are black lines in the light spectrum where helium has absorbed light
What is the light spectrum starting with smallest wavelength and biggest frequency
Purple Blue Green Yellow Orange Red
What colour do stars appear the further they are from us and why?
Red
because we only see the largest wavelengths which is red as the smaller wavelengths are in front of the star being pushed together which would be purple
What does red shift tell us about distant galaxies?
Thy are moving away from us and the further away the galaxy is the faster it moves
