3 vectors and scalar

20 damped harmonic motion,forced harmonic motion, superposition of SHM

damped harmonic motion

underdamped motion:欠阻尼

critical damped零界阻尼

over damped过阻尼

energy of damped harmonic motion

application of damped oscillation:减震器

forced oscillation

resonance

superposition of SHM

superposition in 2D

24-25 light waves interference

the nature of light

definition

speed of light

reflection

dispersion色散

huygens's principle:惠更斯原理

refraction折射；diffraction衍射

young's double-slit interference

coherent light 相干光

恒定相位关系：相干，激光，从一个源分出

double-slit interference pattern

review of double-slit interference

calulate OPD

interference in thin films

example:

wedge-shaped film

newton's rings

26 light diffraction衍射

single-slit diffraction

example

diffraction intensity

circular apertures and resolution

27 light diffraction&light polarization

diffraction

review 

diffraction gratings

multi-slit interference pattern

example

X-ray

polarization

example

polarization by reflection