Force between two charged particles
Q1Q2/4πεr^2
Change in work done of an electric field
QΔV
Force of a uniform electric field on a single charge
EQ = VQ/d
Relative permativity
Q/Qo
Electric potential
Q/4πεr
Electric potential energy
Q/4πεr^2
Capacitance
Q/V = Aεoεr/d = 4πεR
Energy stored in a capacitor
1/2QV = 1/2CV^2 = Q^2/2c
Charge of a capacitor depending on time
Qo(1-e^-t/RC)
Half time depending on RC
0.69RC
Force between two masses
Gm1m2/r^2
Acceleration due to gravity
F/m = Gm/r^2 = -ΔV/Δr
Work done by gravitational force on a mass
mΔV
Gravitational potential
-Gm/r
Gravitational potential energy
-Gm1m2/r
Velocity
sqrt. GM/r
Kepler’s Third Law
4π^2r^3/GM