PHYSICS FORMULAS
2426

Electron = -1.602 19 × 10-19 C = 9.11 × 10-31 kg Proton = 1.602 19 × 10-19 C = 1.67 × 10-27 kg Neutron = 0 C = 1.67 × 10-27 kg 23 6.022 × 10 atoms in one atomic mass unit e is the elementary charge: 1.602 19 × 10-19 C Potential Energy, velocity of electron: PE = eV = ½ 2 mv 1V = 1J/C 1N/C = 1V/m 1J = 1 N·m = 1 C·V 1 amp = 6.21 × 1018 electrons/second = 1 Coulomb/second 1 hp = 0.756 kW 1 N = 1 T·A·m 1 Pa = 1 N/m2 Power = Joules/second = I2R = IV [watts W] Quadratic Kinetic Energy [J] − b ± b 2 − 4ac x= Equation: KE = 1 mv 2 2 2a
[Natural Log: when eb = x, ln x = b ] n: 10-9 p: 10-12 m: 10-3 µ: 10-6 f: 10-15 a: 10-18

Rectangular Notation:

Z = R ± jX where +j represents

inductive reactance and -j represents capacitive reactance. For example, Z = 8 + j 6Ω means that a resistor of 8Ω is in series with an inductive reactance of 6Ω. Polar Notation: Z = M ∠θ, where M is the magnitude of the reactance and θ is the direction with respect to the horizontal (pure resistance) axis. For example, a resistor of 4Ω in series with a capacitor with a reactance of 3Ω would be expressed as 5 ∠-36.9° Ω. In the descriptions above, impedance is used as an example. Rectangular and Polar Notation can also be used to express amperage, voltage, and power.

To convert from rectangular to polar notation: Given: X - jY (careful with the sign before the ”j”) Magnitude: Angle:

Addition of Multiple Vectors:

r r r r R = Ar+ B + C r Resultant = Sum of the vectors r r Rx = Ax + Bx + Cx x-component A x = A cos θ r r r r Ry = Ay + By + C y y-component A y = A sin θ
R = Rx 2 + Ry 2 θ R = tan −1 Ry Rx or Magnitude (length) of R tanθ R = Ry Rx Angle of the resultant

X 2 + Y2 = M (negative sign carried over −Y from rectangular notation tan θ = X in this example)

Note: Due to the way the calculator works, if X is negative, you must add 180° after taking the