Attractive nuisances can create liability risks. Learn what a home attractive nuisance is and see the most common attractive nuisance examples.
In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average, and in particular one of the Pythagorean means. Typically, it is appropriate for situations when the average of rates is desired. The harmonic mean can be expressed as the reciprocal of the arithmetic mean of the reciprocals. As a simple example, the harmonic mean of 1, 2, and 4 is 3 1 1 + 1 2 + 1 4 = 1 1 3 ( 1 1 + 1 2 + 1 4 ) = 12 7 .
HARMONICS A characteristic of energy generated by a vibration is that there will be a number of frequencies appearing up the frequency spectrum at multiples of the fundamental frequency. These are called Harmonics. The fundamental frequency is also the first harmonic.