# phys2401 formulas

 Law of Reflection θr = θiangle of reflection = angle of incidence Radius of Curvature r = 2f(radius) = 2 * (focal length) Mirror/Thin Lens Equation 1/do + 1/di = 1/f1 / (distance of object) + 1 / (distance of image) = 1 / (focal length) Lateral Magnification m = hi/ho = -di/do(magnification) = (height of image) / (height of object) = -(distance of image) / (distance of object)note: - is sign convention Index of Refraction n = c/v(index of refraction) = (speed of light in vacuum) / (speed of light in given material) Snell's Law n1sinθ1 = n2sinθ2(index of refraction1) * (sine of angle1) = (index of refraction2) * (sine of angle2) note: if n2 > n1, then θ2 < θ1.ie: if light goes to a medium with higher n (and speed is less), ray is bent toward the normal and vice versa. Critical Angle sinθc = n2/n1(sine of critical angle) = (index of refraction2) / (index of refraction1) Power of Lens P = 1/f(power) = 1 / (focal point)note: unit is diopter, m-1, (1/m) Angular Magnification/Magnifying Power M = θ'/θ = (h/f)/(h/N)(angular magnification) = θwith lens / θunaided = [(height of object) / (focal length)] / [(height of object) / (near point of eye)]note: N for normal eye is 25 Wavelength in Another Medium λn = λ/n(wavelength in new medium) = (wavelength in air) / (index of refraction of new medium) Interference Equations Constructive: dsinθ = mλDestructive: dsinθ = (m+1/2)λ(distance between slits) * (sine of angles made with horizontal) = (order + n) * (wavelength)note: m = 0, 1, 2, ... Diffraction Equation Dsinθ = mλ(slit width) * (sine of angle of rays) = (order) (wavelength)note: m = +/-1, +/-2, +/-3, ... Rayleigh Criterion λ = 1.22λ/D(resolvable angle) = 1.22 * (wavelength) / (diameter of lens) Resolving Power (microscope) RP = s = fθ = 1.22λf/D(resolving power) = (actual distance barely resolvable) = (focal point) * (subtended angle) = 1.22 * (wavelength) * (focal length) / (diameter of lens) Diffraction Grating equation dsinθ = mλ(distance between slits) * (sine of angles made with horizontal) = (order) * (wavelength)note: m = 0, 1, 2, ... Bragg Equation 2dsinϕ = mλ(distance between atoms) * (sine of measured angle) = (order) * (wavelength)note: m = 0, 1, 2, ... Polarization Equation I = I0cos2θ(intensity of polarized light) = (incoming intensity) * (cosine of angle between polarizer and incoming light)2 Brewster's Law tanθp = n2/n1(tangent of polarizing angle) = (index of refraction2) / (index of refraction1) AuthorPowLow ID35611 Card Setphys2401 formulas Description(Important) formulas for Physics 2401 Exam 1 (Ch.32-35) Updated2010-09-19T04:21:01Z Show Answers