Charge Capacitor ```Coulomb's law, force of attraction/repulsion F = kQ₁Q₂/r² Q₁ and Q₂ are the charges in coulombs F is force in newtons r is separation in meters k = 8.99e9 Nm²/C² k = 1/(4πε₀) where ε₀ = 8.8542e-12 F/m = permittivity of space (F/m) in presence of dielectric, that is modified to F = Q₁Q₂/(4πε₀εᵣr²) or F = kQ₁Q₂/(εᵣr²) εᵣ is dielectric constant (vacuum = 1) Potential energy between two charges, in Joules U = kQ₁Q₂/r Q₁ and Q₂ are the charges in coulombs r is separation in meters k = 8.99e9 Nm²/C² between three charges it is U = (kQ₁Q₂/r₁₂) + (kQ₂Q₃/r₂₃) + (kQ₁Q₃/r₁₃) (assume – for unlike charges) Charge moving in an electric field E = QV 1 coulomb moving thru a 1 volt change = 1 J for a constant electric field Ed = Fd/q = W/q = ΔV E is electric field d is distance moved F is force q is charge W is work done V is voltage Electric field The strength or magnitude of the field at a given point is defined as the force that would be exerted on a positive test charge of 1 coulomb placed at that point; the direction of the field is given by the direction of that force. E = F/Q = kQ/r² Q = F/E F = QE in Newtons/coulomb OR volts/meter k = 1/4πε₀ = 8.99e9 Nm²/C² 1 C = 6.242e18 electrons 1 electron charge = 1.602e-19 C Potential is The work per unit of charge required to move a charge from a reference point to a specified point, measured in joules per coulomb or volts. reference point is usually infinity. The electric potential for a system of point charges is equal to the sum of the point charges' individual potentials. The Potential from a charge is V = kQ/r in volts k = 1/4πε₀ = 8.99e9 Nm²/C² r is separation in meters q is charge in coulombs Energy in a particle E = hf, where h = Plank's constant 6.626e-34 Js E = hc/λ E is the energy of the particle in Joules f is frequency, λ is wavelength in meters ``` Home Area, Volume Atomic Mass Black Body Radiation Boolean Algebra Calculus Capacitor Center of Mass Carnot Cycle Charge Chemistry   Elements   Reactions Circuits Complex numbers Constants Curves, lines deciBell Density Electronics Elements Flow in fluids Fourier's Law Gases Gravitation Greek Alphabet Horizon Distance Interest Magnetics Math   Trig Math, complex Maxwell's Eq's Motion Newton's Laws Octal/Hex Codes Orbital Mechanics Particles Parts, Analog IC   Digital IC   Discrete Pendulum Planets Pressure Prime Numbers Questions Radiation Refraction Relativistic Motion Resistance, Resistivity Rotation Series SI (metric) prefixes Skin Effect Specific Heat Springs Stellar magnitude Thermal Thermal Conductivity Thermal Expansion Thermodynamics Trigonometry Units, Conversions Vectors Volume, Area Water Wave Motion Wire, Cu   Al   metric Young's Modulus