Particles and Waves Flashcards
Forces on charged Particles
Ew=QV
Ek=1/2mv²
Alpha decay
emits product and He₂⁴
Beta decay
emits product and e ₋₁ ⁰
Gamma emission
product stays the same
mass lost or energy released by nuclear reaction
e=mc²
Irradiance
Power per unit of area incident on a surface
I=P/A
Point Source of light
I=k/d² or I₁d₁²=I₂d₂²
h=
Planck’s constant
photoelectric effect
E=hf
Ek= hf - hf₀
Ek=1/2mv²
v=fλ
frequency of radiation emitted or absorbed
E=hf
E₂-E₁=hf
Angle of incidence or angle of refraction
n= sinθ₁/sinθ₂
Critical angle or refractive index
Sinθ꜀=1/n
n=
refractive index
diffraction grating
dSinθ=mλ
d=
distance between
m=
order maxima number
sinθ₁=
angle of incidence
What exist between charged parallel plates
electric fields
Do electric fields exist between or around charged particles
around
+ L or R?
Left
- L or R?
Right
thumb
1st
2nd
T- Direction of motion
1st- Field (into or out of page)
2nd- Current
Define Potential Difference
work done per unit charge
V=W/Q
Moving charge produces
a magnetic field
how do fusion reactors contain high temperature charge particles (plasma)
using a ring of magnetic fields
What is the photoelectric effect evidence for
the particle model of light
The particle model of light suggests?
Light is made up of a constant stream of photons
What is photoemission
photons, provided they are over the threshold frequency and work function, can eject photons from the surface of materials
Define Threshold frequency
minimum frequency of a photon required for photoemission.
Define Work function
minimum energy of a photon required for photoemission.
What is evidence for the wave model of light?
Interference
Coherent Waves
Constant phase relationship
Constructive interference
when coherent waves meet in
phase, peaks of waves meet peaks
and troughs meet troughs.
Destructive interference
when coherent waves meet out of phase, peaks meet troughs.
Produced when path difference is a whole number
maxima
Bohr model
Electrons occupy discrete orbits. (have energy levels)
innermost energy level
Ground state n=1
Ionisation
When an electron has sufficient energy to escape an atom
as electrons grow further from the nucleus
Potential energy increases
Absolute refractive index
the ratio of the speed of light in a
vacuum to the speed of light in the medium.
Angle of incidence
Going into (from normal to line)
Angle of Refraction
After it has entered (from normal to line)
refractive index increases
f of incident radiation increases
Aoi that produces and Aor of 90◦
Critical angle
Frequency or energy gained or lost by an electron/photon
E=hf
hf₀=
work function
Energy of a photoelectron emitted from material
Ek= hf - hf₀
Ek=1/2mv²
What is path difference?
distance between two order maximas’
