Unit 1 - Physics.

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SUMMER

Cards (112)

what do waves do?
transfers energy from one place to another without matter
what are the 5 key terms for labelling a transverse wave ?
propagation, amplitude, wavelength, crest, trough
what is wavelength?
the distance of one complete wave
what is propagation?
the direction in which the wave is travelling in.
what is the crest of a wave?
the top point of the wave which can also be known as the peak
what is the trough of a wave?
the lowest part of the wave
what is amplitude? 2 definitions
the height of the crest or depth of the trough, the maximum displacement from its undistributed resting position
what is frequency?
the number of complete waves that pass a fixed point per second
what is wavespeed?
the distance the wave travels every second
what is the wave equation?
wavespeed = frequency x wavelength
what are the units of the wave speed equation?
m/s, Hz and m
what 4 types of waves are there?
longitudinal, transverse, mechanical, electromagnetic
what is a longitudinal wave?
a wave that oscillates / vibrates which is parallel to the direction of the wave
examples of longitudinal waves?
sound waves, p-seismic, ultrasound
what are transverse wave?
a wave that oscillates / vibrates perpendicular to the direction of the wave at 90 degrees
examples of transverse waves? 
light waves, water waves, s-seismic. electromagnetic
what do longitudinal waves show? 
compression and rarefaction
what is compressions and rarefactions?
compressions are the compressed lines on the wave which are closest together. rarefactions are the spread out lines which are the furthest apart
what is the definition for periodic time?
the time required to complete a full wave cycle
what is the definition of phase difference?
the amount by which a wave leads or lags another one.
phase difference circle?
1st - 90 degrees, 0.5 radians, 0.25 wavelength
2nd - 180 degrees, 1 radian, 0.5 wavelength
3rd - 270 degrees, 1.5 radians, 0.75 wavelength
4th - 360 degrees, 2 radians, 1 wavelength
what is displacement?
the distance moved by a wave from its original position during an oscillation
what is coherence?
the superposition of the waves gives a visible constructive interference pattern and must have the same wavelength and frequency and have a constant phase difference
what is path difference?
the difference in the distance travelled by different waves to reach a certain point is influenced by the wavelength
waves with a higher frequency has shorter wavelengths which travels a larger distance. waves with a lower frequency has longer wavelengths which travels a short distance
what is superposition?
the displacement of two waves and equals to the individual wave displacements
what are interferences?
the two consequences for superposition
what is constructive interference ?
when two waves are in phase by one wavelength. this is where the waves overlap perfectly where crest meets another
what is destructive interference?
occurs when the waves are out of phase by half a wavelength. each wave cancels each other out by use of superposition
what is transmission?
wave energy passing through an object
what are wavefronts?
waves that are 1 wavelength apart and are at perpendicular to the direction of propagation.
what is meant by diffraction?
the spreading out and separation of waves in all directions through a gap or slit
what do diffraction gratings do?
determines the wavelength of different light colours from diffraction angles
red and purple light frequencies and differences on the visible light spectrum?
red light has the lowest frequency and the largest wavelength which diffracts the most. purple light has the highest frequency and the smallest wavelength which diffracts the least
what are emission spectra used for?
to identify vaporised heavy metal elements
what is the number of planck's constant?
6.63x10-34 Js
what is the speed of light ?
3 x 10 8
steps to use energy equation involving plancks constant and frequency ?
calculate energy difference
use equation to find frequency
use wavespeed equation to calculate wavelength
what are stationary waves ?
waveforms that store energy rather than transferring the energy, they oscillate with waves becoming smaller until it stops
what are progressive waves?
waveform that travels and transfers energy from one position to another