Units, Constants, and Conversions

Back to Physics Formulas and Derivations

$LaTeX: \underline{\textbf {Basic SI Units}}$ $\underline{\textbf {Basic SI Units}}$

Length: meter [m]

Mass: kilogram [kg]

Time: second [s]

Current: ampere [A]

Temperature: kelvin [K]

Amount of Substance: mole [mol]

Luminous Intensity: candela [cd]

$LaTeX: \underline{\textbf {Derived SI Units: Measurements}}$ $\underline{\textbf {Derived SI Units: Measurements}}$

Area: [m²]

Volume: [m³]

Linear Mass Density: [kg/m]

Surface Mass Density: [kg/m²]

Volumetric Mass Density: [kg/m³]

$LaTeX: \underline{\textbf {Derived SI Units: Physics I}}$ $\underline{\textbf {Derived SI Units: Physics I}}$

Velocity: [m/s]

Acceleration: [m/s²]

Force: [N] = [kg*m/s²]

Joule: [J] = [N*m] = [kg*m²/s²]

The unit Joule is for energy. The units of Torque result in N*m which is equivalent to J, however it is not Joules because Torque is not energy.

Watt: [J/s] = [kg*m³/s²]

Spring Constant: [N/m]

Momentum/Impulse: [kg/m³]

Torque: [N*m]

Moment of Inertia: [kg*m²]

Angular Displacement: [rad]

Angular Velocity: [rad/s]

Angular Acceleration: [rad/s²]

Period/Frequency: [hz] = [1/s] = [s^-1]

$LaTeX: \underline{\textbf {Derived SI Units: Physics II}}$ $\underline{\textbf {Derived SI Units: Physics II}}$

Voltage: [V] = [J/C]

Electric Field: [N/C] = [V/C]

Electric Flux: [N*m²/C]

Electric Charge: [C] = [A*s]

Resistance: [ $LaTeX: \Omega$ $\Omega$ ] = [V/A]

Capacitance: [F] = [C/V]

Electric Density: [J/m³]

RC Time Constant: [ $LaTeX: \Omega$ $\Omega$ *F] = [s]

Magnetic Field: [T] = [N/(A*m)]

Magnetic Flux: [Wb] = [T*m²]

Inductance: [H] = [V*s/A]

$LaTeX: \underline{\textbf {Constants: Physics I}}$ $\underline{\textbf {Constants: Physics I}}$

Free Fall: g = 9.8 m/s²

Gravitational Constant: G = 6.674 X 10^-11 N*m²/kg²

Mass of Earth: m_E = 5.97 X 10²⁴ kg

Radius of Earth: r_E = 6.37 X 10⁶ m

Mass of Moon: m_M = 7.35 X 10²² kg

Radius of Moon: r_M = 1.74 X 10⁶ m

Mass of Sun: m_S = 1.989 X 10³⁰ kg

Radius of Sun: r_S = 6.96 X 10⁸ m

Earth-Sun Distance: r_ES = 1.496 X 10¹¹ m

Earth-Moon Distance: r_EM = 3.84 X 10⁸ m

Standard Atmospheric Pressure: atm = 1.013 X 10⁵ Pa

Gas Constant: R = 8.314 J/(mol*K)

$LaTeX: \underline{\textbf {Constants: Physics II}}$ $\underline{\textbf {Constants: Physics II}}$

Coulomb's Constant: k_e = 8.99 X 10⁹ n*m²/C²

Permittivity of Free Space: $LaTeX: \epsilon$ $\epsilon$ ₀ = 8.854 X 10^-12 C²/(N*m²)

Charge of an Electron: q_e = -1.602 X 10^-19 C

Charge of a Proton: q_p = 1.602 X 10^-19 C

Mass of an Electron: m_e = 9.109 X 10^-31 kg

Mass of a Proton: m_p = 1.673 X 10^-27 kg

Electron Volt: eV = 1.602 X 10^-19 J

Permeability of Free Space: $LaTeX: \mu$ $\mu$ ₀ = 4 $LaTeX: \pi$ $\pi$ X 10^-7 T*m/A

Planck's Constant: h = 6.626 X 10^-34 J*s

Speed of Light in a Vacuum: c = 2.9979 X 10⁸ m/s

$LaTeX: \underline{\textbf {Unit Names}}$ $\underline{\textbf {Unit Names}}$

The unit [N] stands for "newton"
The unit [J] stands for "joule"
The unit [C] stands for "coulomb"
The unit [F] stands for "farad"
The unit [T] stands for "tesla"
The unit [Wb] stands for "weber"
The unit [H] stands for "henry"

$LaTeX: \underline{\textbf{Conversions: Length}}$ $\underline{\textbf{Conversions: Length}}$

1 in = 2.54 cm

1 m = 3.281 ft

1 mi = 1.609 km

1 mi = 5280 ft

1 lightyear = 9.461 X 10¹⁵ m

$LaTeX: \underline{\textbf{Conversions: Area}}$ $\underline{\textbf{Conversions: Area}}$

1 m² = 10⁴ cm²

1 m² = 10.76 ft²

1 ft² = 0.0929 ft²

1 ft² = 144 in²

1 in² = 6.452 cm²

$LaTeX: \underline{\textbf{Conversions: Volume}}$ $\underline{\textbf{Conversions: Volume}}$

1 m³ = 106 cm³

1 m³ = 6.102 X 104 in³

1 ft³ = 1728 in³

1 ft³ = 2.83 X 10^-2 m³

1 L = 1000 cm³

1 L = 1.0576 qt

1 L = 0.0353 ft³

1 ft³ = 7.481 gal

1 gal = 3.786 L

$LaTeX: \underline{\textbf{Conversions: Mass}}$ $\underline{\textbf{Conversions: Mass}}$

1 slug = 14.59 kg

1 u = 1.66 X 10^-27 kg

1 u = 931.5 M*eV/c²

$LaTeX: \underline{\textbf{Conversions: Force}}$ $\underline{\textbf{Conversions: Force}}$

1 N = 0.2248 lb

1 lb = 4.448 N

$LaTeX: \underline{\textbf{Conversions: Pressure}}$ $\underline{\textbf{Conversions: Pressure}}$

1 atm = 760 mm Hg

1 atm = 1.013 X 10⁵ N/m²

1 Pa = 1 N/m²

1 Pa = 1.45 X 10^-4 lb/in²

$LaTeX: \underline{\textbf{Conversions: Time}}$ $\underline{\textbf{Conversions: Time}}$

1 hr = 3600 s

1 day = 24 hr

1 day = 8.64 X 10⁴ s

1 day = 1.44 X 10³ min

1 yr = 3.16 X 10⁷ s

$LaTeX: \underline{\bf Common\ Densities\ at\ 0^\circ C\ and\ 1\ atm}$ $\underline{\bf Common\ Densities\ at\ 0^\circ C\ and\ 1\ atm}$

Air: 1.29 kg/m³

Aluminum: 2.70 X 10³ kg/m³

Benzene: 0.879 X 10³ kg/m³

Brass: 8.4 X 10³ kg/m³

Copper: 8.92 X 10³ kg/m³

Fresh Water: 1.00 X 10³ kg/m³

Gold: 19.3 X 10³ kg/m³

Helium Gas: 1.79 X 10^-1 kg/m³

Hydrogen Gas: 8.99 X 10^-2 kg/m³

Ice: 0.917 X 10³ kg/m³

Iron: 7.86 X 10³ kg/m³

Lead: 11.3 X 10³ kg/m³

Mercury: 13.6 X 10³ kg/m³

Nitrogen Gas: 1.25 kg/m³

Osmium: 22.6 X 10³ kg/m³

Platinum: 21.4 X 10³ kg/m³

Silver: 10.5 X 10³ kg/m³

Tin: 7.30 X 10³ kg/m³

Uranium: 19.1 X 10³ kg/m³

$LaTeX: \underline{\textbf{Speed of Sound in Gasses}}$ $\underline{\textbf{Speed of Sound in Gasses}}$

Hydrogen (0 $LaTeX: ^\circ$ $^\circ$ C): 1.286 X 10³ m/s

Helium (0 $LaTeX: ^\circ$ $^\circ$ C): 972 m/s

Air (0 $LaTeX: ^\circ$ $^\circ$ C): 331 m/s

Air (20 $LaTeX: ^\circ$ $^\circ$ C): 343 m/s

Oxygen (0 $LaTeX: ^\circ$ $^\circ$ C): 317 m/s

$LaTeX: \underline{\bf Speed\ of\ Sound\ in\ Liquids\ at\ 25^\circ C}$ $\underline{\bf Speed\ of\ Sound\ in\ Liquids\ at\ 25^\circ C}$

Glycerol: 1904 m/s

Water: 1493 m/s

Mercury: 1450 m/s

Kerosene: 1324 m/s

Methyl Alcohol: 1143 m/s

Carbon Tetrachloride: 926 m/s

$LaTeX: \underline{\textbf{Speed of Sound in Solids (large quantities)}}$ $\underline{\textbf{Speed of Sound in Solids (large quantities)}}$

Pyrex Glass: 5640 m/s

Iron: 5950 m/s

Aluminum: 6420 m/s

Brass: 4700 m/s

Copper: 5010 m/s

Gold: 3240 m/s

Lead: 1960 m/s

Rubber: 1600 m/s

$LaTeX: \underline{\bf Dielectric\ Constants\ (\kappa)\ at\ 20^\circ C}$ $\underline{\bf Dielectric\ Constants\ (\kappa)\ at\ 20^\circ C}$

Air: 1.00059

Bakelite: 4.9

Fused Quartz: 3.78

Mylar: 3.2

Neoprene Rubber: 6.7

Nylon: 3.4

Paper: 3.7

Polystyrene: 2.56

Porcelain: 6

Pyrex Glass: 5.6

Silicone Oil: 2.5

Teflon: 2.1

Vacuum: 1.00000

Water: 80

$LaTeX: \underline{\bf Resistivities\ at\ 20^\circ C}$ $\underline{\bf Resistivities\ at\ 20^\circ C}$

Silver: 1.59 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Copper: 1.7 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Gold: 2.44 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Aluminum: 2.82 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Tungsten: 5.6 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Iron: 10 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Platinum: 11 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Lead: 22 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Carbon: 3.5 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Silicon: 2.3 X 10^-8 $LaTeX: \Omega$ $\Omega$ *m

Glass: 10¹⁰ - 10¹⁴ $LaTeX: \Omega$ $\Omega$ *m

Hard Rubber: 10¹³ $LaTeX: \Omega$ $\Omega$ *m

Sulfur: 10¹⁵ $LaTeX: \Omega$ $\Omega$ *m

Quartz (fused): 70 X 10¹⁶ $LaTeX: \Omega$ $\Omega$ *m

$LaTeX: \underline{\textbf{Approximate Wavelengths of Light}}$ $\underline{\textbf{Approximate Wavelengths of Light}}$

Radio Waves: 10⁴ m - 0.1 m

Microwaves: 0.3 m - 10^-4 m

Infrared: 10^-3 m - 7 X 10^-7 m

Red: 625 X 10^-9 m - 700 X 10^-9 m

Orange: 590 X 10^-9 m - 625 X 10^-9 m

Yellow: 560 X 10^-9 m - 590 X 10^-9 m

Green: 485 X 10^-9 m - 560 X 10^-9 m

Blue: 430 X 10^-9 m - 485 X 10^-9 m

Violet: 400 X 10^-9 m - 430 X 10^-9 m

Ultraviolet: 4 X 10^-7 m - 6 X 10^-10 m

X-Rays: 10^-8 m - 10^-12 m

Gamma Rays: 10^-10 m - 10^-14 m

$LaTeX: \underline{\bf Indices\ of\ Refraction\ -\ Solids\ at\ 20^\circ C}$ $\underline{\bf Indices\ of\ Refraction\ -\ Solids\ at\ 20^\circ C}$

Diamond: 2.419

Fluorite: 1.434

Fused Quartz: 1.458

Glass, Crown: 1.52

Glass, Flint: 1.66

Polystyrene: 1.49

Sodium Chloride: 1.544

(Good for light of wavelength 589 nm in a vacuum)

$LaTeX: \underline{\bf Indices\ of\ Refraction\ -\ Liquids\ at\ 20^\circ C}$ $\underline{\bf Indices\ of\ Refraction\ -\ Liquids\ at\ 20^\circ C}$

Benzene: 1.501

Ethyl Alcohol: 1.361

Glycerin: 1.473

Water: 1.333

(Good for light of wavelength 589 nm in a vacuum)