Physics 2 UF formula sheet, Cheat Sheet of Physics

Download Physics 2 UF formula sheet and more Cheat Sheet Physics in PDF only on Docsity! PHY2049 Formulas: Sheet 1 Chapter 21 – 23 (Electric forces and fields, Gauss’ law) Coulomb’s Law 2 2 0 ˆ ˆ 4 kQq Qq r rπε = ≡F r r (point charge) r̂ = unit vector from Q to q. Electric field q=F E (general) 2 2 0 ˆ ˆ 4 kQ Q r rπε = ≡E r r (single point charge Q) 2 2 ˆ ˆ or i i i i kq kdq r r = =∑ ∫E r E r (point charges or continuous) Electric dipole cosU pE θ= − ⋅ = −p E sinpEτ τ θ= × =p E Gauss’ law encl 0 E i ii S Qd ε Φ = ⋅ = ⋅ =∑ ∫E A E A "electric flux"EΦ = Chapter 24 – 25 (Electric potential, capacitors) Work 2 21 1 2 2 f f i f ii W d K K mv mv= ⋅ = − = −∫ F s Conservative force f f i i i f fi U U d U K U K− = − ⋅ → + = +∫ F s (energy conservation) Electric potential 0 (general) (point charge ) 4 U kQ QV V Q q r rπε = = ≡ Potential difference ( )f i f iV V VΔ ≡ − = − ⋅ −E x x (E constant) f f i i V V d− = − ⋅∫ E s (E variable) E field from V x y z V V VE E E x y z ∂ ∂ ∂ = − = − = − ∂ ∂ ∂ Capacitors 0 AC d ε = (flat plates) ( ) 02 ln / LC b a πκε = (cyl shell) 04 abC b a πκε= − (sph shell) Capacitors (cont) eq 1 2 eq 1 2 1 1 1(parallel) (series)Eq CV E C C C C C C C C κ κ = → → = + = + Energy 2 2 21 1 02 2(energy) (energy density) 2E E qU CV u E C ε= = = Chapter 26 – 27 (Electric current, circuits) Current (basic def) (using current density) S dqi i JA i d dt ≡ = = ⋅∫ J A Current density 1 (using conductivity or resistivity )ρσ σ ρ= =J E E Drift velocity 2/ (resistivity)e d e eJ en v m e nρ τ= = Resistance eq 1 2 eq 1 2 1 1 1(series) (parallel)LV iR R R R R A R R R ρ = = = + = + Temp dependence ( )0 0 0T Tρ ρ ρ α− = − RC circuits ( )/ / max max1 (charging) (discharging)RC RCt t RC RC q q e q q eτ ττ − −= = − = Circuits (1) Current entering junction = current leaving junction (2) 0 (over loop)iiV =∑ Power in circuit 2(general power eqn) (power lost in resistor)P iV P i R= = Chapter 28 – 29 (Magnetic fields) Magnetic force sin (charge) sin (current)q F qvB i F iLBφ φ= × = = × =F v B F L B Magnetic dipole (current loop)NiAμ = sin (torque) cos (potential energy)B U Bτ μ τ μ θ μ μ θ= × = = − ⋅ = −B B Generating B field 0 0 2 2 ˆ sin (Biot-Savart law) 4 4 id idsd dB r r μ μ θ π π × = = s rB 0 0 enc (Ampere's law) (long wire) 2 id i B r μμ π ⋅ = =∫ B s 0 0 0(circular loop) (partial loop) (solenoid) 2 4 i iB B B ni R R μ μ φ μ π = = = Force between currents 0 2 a b ab i i LF d μ π = B field of dipole ( ) 0 32 z z μ μ π =B (very far from dipole)