Physics and Math 8 Light and Optics

Physics and Math 8: Light and Optics Electromagnetic Spectrum Geometric Optics Electromagnetic Transverse waves that consist of an oscillating electric Waves: field and an oscillating magnetic field. The two fields are perpendicular to each other and to the direction of propagation of the wave. Reflection: Rebounding of incident light waves at a medium’s boundary Law of q ' =" q 2 Reflection: Electromagnetic The range of frequencies and wavelengths found in EM Spectrum: waves. small l ¬ high energy ¬ EM Spectrum: high l low energy Mirror Image Produced Position Cause Concave Real Inverted Object’s position is greater than the focal length Spherical Mirrors: Note: Gamma, X-ray, and higher UV are ionizing. They can liberate electrons from nearby atoms and create free radicals. Virtual Upright Convex Virtual Upright & smaller Plane Virtual Upright & same size Visible Spectrum: Object’s position is less than the focal length Can think of these as spherical mirrors with infinite radii of curvature Wavelength (nm) Hydrogen Lyman: Ultraviolet, n = 1 Spectral Series: Balmer: Visible, n = 2 Paschen: Infrared, n = 3 Acrostic “Loves Beer Pong”, then n = 1, n = 2, n = 3 ' Rydberg Formula: ℎ"𝑓 =𝑅"( . ( )*+,- − ' . (*+*0*,- ) Diffraction Diffraction: The bending and spreading out of light waves as they pass through a narrow slit. Diffraction may produce a large central light fringe surrounded by alternating light and dark fringes with the addition of a lens. Interference: When waves interact with each other, the displacements add together in a process called interference. Young’s Double- Shows the constructive and destructive interference of waves Slit Experiment: that occur as light passes through parallel slits, resulting in minima (dark fringes) and maxima (bright fringes) of intensity. Polarization Plane-Polarized A polarizing filter only lets light through if the E field of Light: the wave aligns with the openings in the filter. The E fields of the exiting light oscillate along the same axis. Circular All of the light rays have electric fields with equal Polarized Light: intensity but constantly rotating direction. Circularly polarized light is created by exposing unpolarized light to special pigments or filters. Plane-Polarized Light Refraction: The bending of light as it passes from one medium to another. The speed of light changes depending on index of refraction of the medium. This speed change causes refraction. The amount of refraction depends on the wavelengths involved. Index of refraction: 𝑛 =" 4 5 c=speed"of"light"in"vacuum 𝑣 =speed"of"light"in"the"medium Dispersion: When various wavelengths of light separate from each other. Snell’s Law: The law of refraction. There is an inverse relationship between the index of refraction and the sine of the angle of refraction (measured from the normal) 𝑛' sin( q ' ) =𝑛2 sin( q2 ) Total Internal When light cannot be refracted out of a medium and is instead Reflection: reflected back inside the medium. Occurs when light moves from a medium with a HIGHER index of refraction to a medium with a LOWER index of refraction with a high incidentq. Critical The minimum incident angle at which total reflection occurs. Angle: q 4 = sinH'((. ) (I Lenses: Refract light to form images of objects. Thin symmetrical lenses have focal points on each side. Lens Image Produced Position System Convex Real Inverted Converging system Virtual Upright Converging system Virtual Upright Diverging system Concave Circular-Polarized Light F = focus f = focal length ' "𝑓 =" "𝑟 2 Lensmaker’s Lenses with non-negligible thickness require the lensmaker’s eq. Equation: ' = (𝑛 − 1)(' −" ' ) K MI M