PHYS 0175 1st Edition Lecture7Outline of Last Lecture II. Electron Oscillating about a ring of chargeIII. Electric Field of infinite charged plateIV. Electric field between two infinite charged parallel platesV. Acceleration of protonVI. Deflecting chargesOutline of Current Lecture VII. FluxVIII.Flux of Velocity FieldIX. Flux of Electric FieldX. Relation Between Electric Flux and ChargeXI. Guass’ IdeaXII. Gauss’ law XIII. Sign of electric fluxCurrent LectureII. Fluxa. Volume flow rate of electrical chargeb. Area per unit timec. If capturing water flow with rectangle-Depends orientation/position of rectangle relative to velocity of waterIII. Flux of Velocity Fielda. dV/dt=vA if exactly perpindicularb. dV/dt=vAcos-thetai. tiltedii. =0 if theta=90iii. flux=v*Aiv. n-hatdirection of vector going out from surface”normal”IV. Flux of Electric Fielda. If uniform and flat surfacei. Flux=E*Aii. Surface integral1. Must be closed surface to have charges2. External charges not affect3. SI units for flux: kg*m^3*s^-3*A^-1iii. Dot product1. Produces a scalar2. Rids both direction about the vectorsV. Relation Between Electric Flux and Chargea. Purpose of flux is to measure the charges within the “box” which is imaginary if a Gaussian surfaceb. Flux does not matter what volume, not change fluxc. Neither is it dependent upon shapei. Number of flux lines same, just more or lessspace in betweend. Only changing the magnitude of charge inside box can affect fluxe. If not flux either no charges or neutralized by opposite chargesf. If from external source no flux because inward flux cancels outward fluxi. Equal and opp VI. Guass’ Ideaa. Take any distribution of chargeb. Surround with any imaginary surfacec. Must be closedd. Electric field is related to total net charge enclosede. Can choose any symmetric surfaceVII. Gauss’ law a. Electric flux=closed surface integral of E*dA=Q/permittivity constanti. Any random shape that fits the problemii. Using spherical symmetryVIII.Sign of electric fluxa. Outward if flux is positiveb. Inward if flux is
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