Quanta and waves Flashcards
Evidence of quantum theory
black body radiation curves
the UV carastrophe
experimental evidence for wave-particle duality
-the photoelectric effect (light behaving as particles)
-electron diffraction patterns (particles behaving as waves)
formula for particles moving at non-right angles to field
F=qBsinx
What happens if a particle is moving parallel to a field
It will not be deflected
What does F=qvB equal
Fc=mv^2/r
as the force exerted is a centripetal force
SHM graphs for s, v, a against t
For a spring that has been raised
s: starts at 1
v: starts at 0 and goes down
a: starts at -1
F=-ky graph
negative gradient meeting (0,0)
What does the angular frequency and period of oscillation (SHM) not depend on?
the displacement of the object from equilibrium
SHM: When is velocity at a maximum and when is it 0?
maximum when y=0
0 wheny=A or -A
When is Ek and when is Ep at their maximum?
What does Etotal equal?
Ek: y=0
Ep: y=A or -A (Ek=0)
Etotal=Ep+Ek
Nodes-points and anti-nodes-points
Nodes-points: Minimum (0) disturbance on a stationary wave
Anti-nodes-points: Maximum disturbance on a stationary wave
Where will standing waves form? And what do these frequencies depend on?
At particular frequencies known as resonant frequencies.
They depend on many factors-length of tube, tension in string, volume of air
First resonant frequency=first harmonic/fundamental frequency
What do we need for constructive and destructive interference
coherent sources-sources of waves with a constant phase relationship
2 types of interference
Interference by division of wavefront: e.g. double slit or grating
Interference by division of amplitude: uses optical path difference
What is interference by division of amplitude?
-splitting the ray into two via reflection and refraction
-The amplitude of the ‘split’ beams is less than the original
