P1.5 Flashcards
What are waves?
Oscillations or vibrations of particles.
With a transverse wave, what direction to the way the wave travels are the oscillations?
Perpendicular (like string)
With a longitudinal wave, what direction to the way the wave travels are the oscillations?
The same (like a spring)
What is an example of a transverse wave?
Water waves
What is an example of a longitudinal wave?
Sound waves
What are 3 examples of electromagnetic waves?
Radio waves
Micro waves
Gamma rays
Are electromagnetic waves transverse or longitudinal?
Transverse
Can electromagnetic waves travel through a vacuum?
Yes
What is the amplitude of a wave?
What is it measured in?
The maximum height of the wave, measured from the middle
M
What is the wavelength of a wave?
What is it measured in?
The shortest distance between two coherent points on the wave
M
What is the frequency of a wave?
What is it measured in?
The number of waves passing a point each second
Hz
What is the electromagnetic spectrum?
Radio waves Micro waves Infrared radiation Visible light Ultraviolet X-rays Gamma rays
What does the angle of incidence equal?
The angle of reflection
What is refraction?
When sound or light waves change speed when they pass from a material of one density to another with a different one
When a sound or light wave moves from an area of low density to an area of high density, which way does it bend?
Towards the normal
When a sound or light wave moves from an area of high density to an area of low density, which way does it bend?
Away from the normal
What is the shortest EM wave?
Gamma rays
What is the longest EM wave?
Radio waves
What are the uses of each EM wave?
Radio waves- TV & radio signals
Micro waves- Heating food & phone communications
Infrared radiation- Remote controls
Visible light- Seeing the world
Ultraviolet- Security pens
X-rays- Detecting broken bones & airport security
Gamma rays- Killing cancerous cells
What is the Doppler effect?
The apparent change in the frequency of a wave caused by the relative motion of the source of the wave and the observer
What is red shift?
Red shift occurs when light or other electromagnetic radiation is increased in wavelength, or shifted to the red end of the spectrum.
How is a change in wavelength and frequency observed when a wave source is moving?
When the source is stationary, waves are released from a single point
-the wavelength frequency is observed as a constant
When the source is moving, the point at which the waves are released is changed every time.
What is CMBR?
Microwaves coming from every direction in space.
