Units.
Basic units.
Mass = Kilogram Kg Length = metre m Time = second s Electric current = ampere A Temperature = Kelvin K Amount of substance = mole mol Luminous intensity = candela cdDerived units.
Quantity Units Formula Symbol Basic unit Frequency Hertz,(cycles per second) Hz 1/s Density Kilogram per cubic meter r kg/m3 Velocity metre/second v m/s Angular velocity radian/sec w rad/s Acceleration metre per second per second a m/s2 Angular acceleration radians per second per second a rad/s2 Volumetric flow rate cubic metre per second Q m3/s Mass flow rate Kilogram per second kg/s Force newton N kg*m/s2 Surface tension newton per metre N/m Kg/s2 Pressure pascal Pa kg/m*s2 Dynamic viscosity newton times seconds per square metre m kg/m*s2 Kinematic velocity metre squared per second n m2/s Work joules, newton metres J kg*m2/s2 Power watt, joule per second W kg*m2/s3 Enthalpy joule per kilogram H m2/s2 Entropy joule per kilogram degree S m2/s2*K Thermal conductivity watt per metre degree k kg*m/s3*K Diffusion coefficient metre squared per second D m2/s Electrical charge coulomb C A*s Electromotive force volt V Kg*m2/A*s3 Electric field strength volt per metre E kg*m/A*s3 Electric resistance ohm W kg*m2/A2*s3 Electrical conductivity amperes per volt metre k A2*s3/kg*m3 Electrical capacitance farad C A2*s4/kg*m2 Magnetic flux weber F kg*m2/s2*A Inductance henry L kg*m2/s2*A2 Magnetic flux density tesla B kg/s2*ADefinition of basic units.
The metre is the length of the path travelled by light in a vacuum during a time interval of 1/299 792 458 of a second. The kilogram is the unit of mass; it is equal to the mass of the International Prototype of the Kilogram, which is almost exactly equal to the mass of 1 litre of pure water. The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. This definition refers to a caesium atom at rest at a temperature of 0 K. The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross section , and placed one metre apart in vacuum, would produce between these conductors a force equal to 2*10-7 newton per metre of length. The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilograms of carbon 12. The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540*1012 hertz and that has a radiant intensity in that direction of 1/683 watts per steradian.Universal constants
Speed of light in a vacuum = 299 792 458 ms-1 Gravitation (Newtonian) = 6.67428(67) x10-11 m3kg-1s-2 Planck's constant = 6.62606896(33) x10-34 J*s Atomic mass unit = 1.66053886(28 x10-27 kg Electron mass = 9.10938215(45) x10-31 kg Electron radius = 2.8179402894(58) x10-15 m Proton mass = 1.672621637(83) x10-27 kg Neutron mass = 1.672621637(83) x10-27 kg Avogadro's number = 6.0221415(10) x10-23 mol-1 Boltzmann constant = 1.3806504(24) x10-23 J*K-1 Faraday constant = 96485.3383(83) C*mol-1 Gas constant = 8.314472(15) J*K-1*mol-1 Elementary charge = 1.602176487(40) x10-19 C Magnetic constant = 1.256637061 x10-6 N*A-2 Electric constant = 8.854187817 x10-12 F*m-1 1 atmospheric pressure = 1.0 x105 N*m-2 Acceleration due to gravity= 9.81 m*s-2 Home page. Speed of Light. String Theory. Next page. Einstein-Relativity. Formulae. Calculus.
