Physics Sound Flashcards
Convex vs convergence
Thin lens equation
Electromagnetic
Electromagnetic waves
Doppler effect
Components: Frequency of the ultrasound wave, frequency is the wave when the source is stationary ( emitted and observed), sleep of the source, and the speed of the detector
Speed of the sound, speed of the moving object, frequencies of the sound waves emitted and observed
Both Doppler and regular ultrasound can detect tissues
Water and air have different indices of ..
Refraction
N increased with density, n water = 1.3, n air = 1
Refraction - bending of light which occurs at the boundary between two different mediums with different values of n.
Of light passed from a high to low n - light bends away from the normal and toward the surface
If incident angel > critical angle => light reflects back to water causing total internal reflection
What is diffraction?
Bending of light around physical corners or very narrow gaps
What is dispersion?
Spreading of light into its different frequencies ( colors) die to differences in the index of refraction for different frequencies of light
What is polarization?
Aligns transverse electromagnetic radiation along a specific orientation such as vertical, horizontal.
Light can be polarized during reflection but polarization doesn’t cause reflection
Process that selectively filters light on its orientation
Path length formula based ont your interference
Types of phase difference on interference
360 - one full wave
180 - half of the wave
If the observed frequency in the Doppler effect is that same as the source frequency then
There is no frequency shift
Radius of curvature formula
R = 2f
F is a focal length
What is magnification of convex lenses in series?
Ability of lenses to produce images that are smaller or larger than a real object that is placed at some distance in front of the others
Mtotal = M1 * M2
How to calculate lens strength?
For a string fixed at both ends, the wavelength of each harmonic is proportional to?
To the string length
Intensity equation
I = P/A = 1/ r^2
Photoelectric effect describes?
The ejection do electrons from a substance due to absorption of electromagnetic radiation with sufficient energy.
The energy needed to eject an electron is fixed via its work function, increasing the energy will increase the kinetic energy of ejected electron
What image concave mirrors form??
Real and inverted
Converging
Point of focus in front of the mirror
What image convex Lens form?
Virtual and upright
Point of focus behind the mirror
What lenses can correct myopia and hyperopia?
Myopia - diverging lens which creates virtual and upright images. The image of the object is located in front of retina, has a focal length shorter
Hyperopia - converging lens that creates real and inverted image
The formation of blurry images due to dispersion is called
Chromatic aberration
Snell law
theta 1 must be greater than theta 2
What is incident light of air?
1
Water is 1.33
Thin lens strength equation
For diverging lenses f and i are negative
For converging lenses f and i are positive
Sound wave energy is directly proportional to ?
Its amplitude squared
E = A^2
By increasing the wave frequency will produce a sound with a higher?
Pitch
The frequency of the sound is directly proportional to what?
Wave speed and temperature
Sound waves travel faster in warmer air and slower in cooler air
Fundamental frequency of a pipe
Antibodies occur at open ends
Nodes occur at closed ends
Resonance in a pipe at one end
What increases with the increasing strings tension?
Frequency
Wave speed formula
v = wavelength * frequency
or
v = wavelength / Period
Total distance the ultrasound travels formula
d = ct
c = speed of sound
t = echo times
If it goes straight and back then we need to divide d = ct by 2
Frequency shift depends on velocities if the train but not
The distance between them
If they travel with the same velocity all the time then the frequency will be the same all the time
What is spherical aberration?
Real lenses are perfectly rounded surfaces which produce an image at a series of focal points not at a single point.
Converging lenses
Rays are entering and exiting the lens periphery ( distant from the principal axis).
In order to correct spherical aberration, need to use asherical lenses at a single point.
What is chromatic dispersion?
Failure of lens to focus multicolored light onto a single point
Can be corrected by using a diverging lenses to increase the thickness of the lens periphery
X ray diffraction?
Through a sample of purified and crystallized material can be used to fester mine 3D molecular structure and packing
Hyperopia
Farsightedness
When optical power (S) of the eye is unable to retract light rays from nearby objects.
Image focuses behind the retina
To treat it we use converging lens that increase optical power to shift the focal length closer to the retina
Myopia
Eye forms an image of distant objects at a focal point in front of the retina
Correcting it with diverging lens to shift the image away from the lens
What waves are sound waves?
Longitudinal
Single slit diffraction pattern
Sound properties are
Longitudinal pressure waves
Greatest in soft materials and increases with distance
Travels most slowly in gases and most quickly in solids
Cannot exist in a vacuum!
Decibel intensity
Logarithmic
For each 10 field decrease = sound intensity decreases by 10 dB
100 fold = 20 db
30 dB = 3*10^3 = 1000
dB = 10 log ( I/ Is)
Doppler effect on velocity and frequency
The frequency shift is positive when the source velocity is negative ( moving closer). And negative when the source velocity is positive ( moving away)
Shock wave therapy definition
Have high frequency waves to cause destructive, high amplitude vibrations within target structures.
For maximum effectiveness, the frequency of the shock waves should match the resonance frequency of the target structure
What is grated diffraction?
Passage of light through an array consisting of numerous slits
May be used to determine the components of polychromatic light and other mixed wavefronts
What is thin film interference?
Multicolored arrays generated by the reflection events that occur within a system composed of two layers of semitransparent media
Influenced by the thickness of the film
Difference between unpolarized light and polarized light
In polarized electric field oscillated in one direction while in unpolarized in all directions
Polarization reduced the amount of light and decreases the amplitude of the electric field oscillations. Doesn’t change the frequency, only the direction
Linear polarization filter blocks electric fields aligned perpendicular to the axis of polarization ( 50% of total intensity)
Longer wavelength cause less
Refraction
And vice versa
How to determine efficiency of one particular step?
Potential energy and kinetic energy in an electric field
