Find the square average of various molecular velocities. The root-mean-square rate is the rate obtained by the quadratic average of various molecular rates and then the root sign. This is a statistical rate, which is meaningless for a single molecule.
If the sign of the root mean square rate is expressed by Vrms, Vrms =√(3kT/m).
Or Vrms =√(3RT/M)
K =1.3806488 (13) ×10-23j/k (Boltzmann constant)
In the statistical analysis of data, sum the squares of all values, find its mean value, and then square it to get the root mean square value. In physics, we often use root mean square value to analyze noise. At the same time, it is also the most commonly used mathematical method to define the effective voltage or current of AC wave.
Extended data:
The root mean square (RMS) can represent the ability of signal transmission power. No matter what waveform, signals with the same mean square eye value send the same power to the resistive load.
The square root of the square average of the instantaneous value of a quantity in a specific time interval. For the number of periodicity, the time interval is one period.
The voltage value of alternating current is a function of time. To describe it completely, we need to use its expression or waveform diagram. However, we are generally concerned about the characterization of voltage work ability, so the effective value of voltage can be obtained by comparing the work ability of alternating current and direct current in a period.
The work done by the periodic voltage U in the last cycle of the resistor R is equal to the work done by the DC voltage U sitting on the resistor R at the same time, so the magnitude of this DC voltage is called the effective value of this periodic voltage.
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