Permittivity, epsi T Q /ML farad per meter sec c /Kg mĪngular frequency omega 1/T radians per second sec Permeability mu ML/Q henry per meter Kg m/c Magnetic vector potential A ML/TQ weber/meter Kg m/sec cĮlectric field intensity E ML/T Q volt/meter or Kg m/sec cĮlectric displacement D Q/L coulomb per c/m Magnetic intensity H Q/LT ampere per meter c/m sec Specific weight gamma M/L T newton Kg/m secĮmf,voltage,potential E ML /T Q volt Kg m /sec cĮlectric resistance R ML /TQ ohm Kg m /sec cĬonductivity sigma TQ /ML mho per meter sec c /Kg mĬurrent density J Q/TL ampere per c/sec m Kinematic viscosity nu L /T square meter m /secĭynamic viscosity mu M/LT newton second Kg/m sec Volume rate of flow Q L /T cubic meter m /sec Luminous flux phi C lumen (4Pi candle cd srĮntropy S ML /T K joule per degree Kg m /sec K _ _ _ _ _Īngular velocity omega 1/T radians per second 1/secĪcceleration a L/T meter per square m/secĪngular acceleration alpha 1/T radians per 1/sec PHYSICAL QUANTITY SYMBOL DIMENSION MEASUREMENT UNIT UNIT EQUATION Thus, there is ambiguity and duplication of symbols. Physics developed over a period of many years by many people from a variety An independent table presents conversionįactors from the MKS measurement system to other measurement systems. Is the name of the unit in the MKS measurement system. Quantity expressed in terms of the fundamental dimensions. The third column is the dimension of the physical The second column is one of the typical symbols usedįor the physical quantity. The table below is organized to present the physical quantity name withĪssociated information. AsĮxpected, centripetal force has the same dimensionality as the force from With the dimensions expected for force from the basic equation F=ma.
mass x (length/time) x (length/time) / length.Ĭombining terms and reducing yields mass x length / time squared. The check is performed byĮxpanding the dimensions, e.g. Second is to check that a consistent system of units is used in the equation.Īn example of a dimensionality check is using the basic equation F=ma toĭetermine that force has the dimension mass x length / time squared, thenĬheck if F=mv /r is dimensionally correct. The dimensionality is independent of the unit system. The checking of a physical equation has two aspects. A few physical dimensions and theĪssociated measurement unit in these three systems are : Is based on centimeter, gram, second measurement. The MKS system is based on meter, kilogram, second measurement. There are a number of systems of units for measuring physical dimensions.
The basic physical dimensionsĪre: length, mass, time, electrical charge, temperature and luminous intensity. That is independent of the units of measurement. All physical quantities have a fundamental dimension Many of these errors can be prevented by performing a dimensionalityĬheck on the equations.
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