Energy of mechanical waves are proportional to the square of the frequency and the square of amplitude
As a wave propagates, the medium of the wave oscillates
velocity = frequency * wavelength
violet (which is actually blue) is the higher energy end of the spectrum, having higher frequency
Due to Rayleigh scattering the sky is orange only during sunrise and sunset and is usually predominantly blue (except in dust storms and such). Since blue light has a higher frequency, thus shorter wavelength, it is more easily "hit" by the air particles in the atmosphere, and scatters. At the beginning/end of the day, the sunlight has to travel further through the atmosphere to reach our eyes. This results in the redder part of the spectrum having more chance to be scattered, and while the bluer part has already been filtered out.
- repeated question- see above-
a wave is a transfer of energy from one point to another through oscillation of media (i.e., the electromagnetic field in case of EMR), where there are no permanent displacement of mass.
crest - highest point, peak - known as compression in a longitudinal wave
trough - lowest point,
wavelength - the distance over which the shape of the wave repeats
resting place - no idea - this may refer to the antinodes of a standing/stationary wave - or the equilibrium position
amplitude - The maximum displacement of a particle in the wave from the equilibrium or rest position (to the crest or trough)
frequency - The reciprocal of the period
Period - The time it takes for the wave to complete a cycle (the shape repeats)
- repeated question -
- repeated -
mechanical
- can be longitudinal or transverse
- require a traditional medium, id est, a medium made of matter
- cannot travel in "vacuum"
- speed is affected by the density of medium - denser medium -> faster wave
electromagnetic
- is transverse, the electric and magnetic components are orthogonal to each other and the direction of propagation
- does not require a traditional medium
- can travel in "vacuum"
- speed is affected by the density of medium - denser medium -> slower wave
- is quantized
There is a third type of wave, gravitational wave, they behave somewhat similarly to EM wave, however this is not taught in high school
Gamma - high energy, used in therapy and imaging
X ray - high energy, used in medical imaging
UV - high energy, used in sterilizing, dentistry and detecting defects in materials
Visible - medium-ish energy, used for seeing, optical fiber, spectrocopy (chemical analysis)
Infrared - medium-low energy, used for heat detection
Microwave - medium-low energy, used for cooking, communication
Radio - low energy, used for radar, communication
*All of them are used in astronomy
- pass -
Different energies of EM wave are given off by different stellar and interstellar objects
Higher energy waves are given off by hot and energetic objects such as globular star clusters or black holes
Lower energy waves are given off by cooler objects, such as brown dwarfs and smaller stars
EM wave can also be streched by the expansion of space, hence older sources are observed with less energetic wavelength, such as seyfert galaxies and cosmic microwave background radiation
Primary waves are longitudinal, secondary waves are transverse and travels slower
These waves travel at different speed depending on the density of the medium
In fact the secondary waves are reflected off the core of the earth
Through tracking the movement of the waves, the layers of earth's interior can be studied, mostly density, depth and phase
Human ear - sorry, not my expertise
Reflection - when a wave hits a surface, it is either transmitted, reflected or absorbed
angle of reflection is equal to angle of incident (measured against the normal)
Refraction - when a wave changes media of differing density, the speed of the wave changes, and so does the direction of propagation
For light waves
sin i / sin r = Vi / Vr = Nr / Ni
where
i = angle of incident
r = angle of refraction
Vi = velocity of incident light
Vr = velocity of refracted light
Ni = refractive index of incident medium
Ne = refractive index of the other medium
Sorry there's just too many question, it started to remind me of my HSC and answering became no longer fun. Hope this was useful. please clicked that button, this response is worth way more than 5 point. oh god, i spent so much time on it.
