physics test 4 Flashcards
huygans’ principle
wave energy travels in waves of constant wavelength
longitudinal
wave action occurs in direction of wave propagation
transverse
wave action occurs perpendicular to direction of wave propogation
wave interference
a phenomenon occurring when 2 waves intersect, producing either a stronger wave or a weaker wave
constructive interference
interference of waves which produces a wave of higher energy
destructive interference
interference of waves which produces waves of lesser energy
diffraction
spreading of light passing through a thin slit or around a sharp edge
diffraction grating
a surface with multiple parallel slits or ridges which by interference separates white light into its colors
resolution
the ability of an optical instrument to distinguish different objects
dispersion
the separation of white light into its colors, as by a prism
spectroscope
a device for viewing the spectrum of light produced by dispersion in a prism of diffraction grating.
polarization
treating light so as to make all of its EM waves vibrate in 1 plane
scattering
spreading of a ray of light as it passes through materials
acoustic energy
the acoustic power passing through a unit area
reference intensity
the lowest acoustic energy audible to a person with good heating; set at 10^-12
decibel level
a logarithmic ratio of acoustic intensity and reference intensity
doppler effect
change in frequency caused by relative motion between a source of sound and a listender
unit cell
smallest building block of a crystal with the characteristic crystalline shape; now known to consist of a few atoms
electrolysis
decomposing a chemical by passing electricity through it
note- avogadro’s number of particles is 6.022 x 10^23
,
faraday’s constant
1 mole of electrons is 96,485 C
cathode rays
streams of electrons emanating from a hot filament inside a vacuum tube
subatomic particle
a particle making up the atom
radioactivity
particles given off by unstable atoms
alpha particle
actually a nucleus of He with
Beta particle
actually electrons
r rays
very high frequency EMR
activity
the number of radioactive disintegrations per second
somatic tissue
body cells other than germ tissue
germ tissue
reproductive cells
background radiation
radioactive emissions from natural sources uncontrolled by man
isotopes
atoms with same number of protons but different number of neutrons
nucleon
particles in the nucleus which is stable; proton or neutron
nuclear force
force in the nucleus holding nucleons together
; also called binding force
binding energy
the energy involved in the binding force
nuclear reaction
a reaction involving a nuclear transformation
decay series
a natural process by which unstable nuclei decay to stable ones through a sequence of steps
induced transmutation
artificial production of a new atoms by bombarding a starter atom
nuclide
any isotope of any element
radionuclide
a radioactive nuclide
fission
the split of a larger nucleus into smaller fragments
controlled chain reaction
a chain reaction whose rate is kept below explosive levels
fusion
the combining of 2 or more smaller nuclei into a larger nucleus
