Waves Flashcards
Wave
A way of transferring energy and momentum from one point to another without the transfer of matter
Mechanical waves
Waves that are made up of particles vibrating
Electromagnetic waves
Waves that are made up of oscillating electric and magnetic fields
Progressive waves
Waves where there is a net transfer of energy and momentum from one point to another
Stationary waves
Waves where there is no net transfer of energy and momentum from one point to another
Longitudinal waves
Waves where the direction of vibration of the particles is parallel to motion
Transverse waves
Waves where the direction of vibration of the particles is perpendicular to motion
Wave displacement
The distance of an oscillating particle from its undisturbed/equilibrium position
Amplitude of a wave
The maximum displacement of an oscillating particle from its equilibrium position
Wavelength
The distance between two consecutive particles at the same phase
(eg. Peak to peak)
Period of a wave
Equal to the time taken for one complete oscillation in a particle in a wave (time taken for each wave)
Frequency
Equal to the number of complete oscillations in one second performed by a particle in a wave
Phase Φ
The point a particle is at within it’s oscillation
Phase difference
The fraction of a cycle between two particles within one or two waves
Refraction
It occurs when a wave passes across a boundary at which the wave speed changes
(Change in speed usually results in a change in direction)
Refractive index
This is equal to the ratio of the wave speeds
(As the speed of light through the material decreases the refractive index increases)
Polaroid
Filters that only let certain waves through them depending on the plane
(Transverse are the only waves that can be polarised)
Unpolarised
When light oscillates at different angles and planes
Plane polarised
Only lets waves through in one plane
(Eg. 3D glasses)
Describe the types of total internal reflection
I > c ray is reflected
I<c ray emerges
I=c ray goes along the edge of block
Intensity
The radiant power passing through a surface per unit area (W/m squared)
What are the wavelength and frequency of a radiowave?
•x10^3m wavelength
•x10^4 hz
What are the wavelength and frequency of microwaves?
• x10^-2 m
• x10^8 hz
What are the wavelength and frequency of infrared?
•x10^-5 m
• x10^12 hz
What are the wavelength and frequency of visible light?
• 0.5x10^-6m
• x10^15
What are the wavelength and frequency of ultraviolet?
• x10^-8 m
• x10^16 hz
What are the wavelength and frequency of x-rays?
• x10^-10 m
• x10^18 hz
What are the wavelength and frequency of gamma rays?
• x10^-12 m
• x10^20 hz
