Seattle Sounders gaining ground in MLS power ranks after Vancouver win Tue Sep 22, 2015 | espnfc.us The Sounders make a big move in this week's rankings, thanks to an emphatic win on the road against the first-place Whi...
In a normal EEG the frequencies are predominately within the range of alpha and beta rhythms at the rate of 8 to 30 hertz (cycles per second). During sleep the brain cells generate higher voltage electrical waves, but the rhythm is slowed down to 2 or 3 hertz, sometimes with short âsleepâ spindles of about 15 hertz.
Frequency describes the number of waves that pass a fixed place in a given amount of time. So if the time it takes for a wave to pass is is 1/2 second, the frequency is 2 per second. If it takes 1/100 of an hour, the frequency is 100 per hour.Usually frequency is measured in the hertz unit, named in honor of the 19th-century German physicist Heinrich Rudolf Hertz.The hertz measurement, abbreviated Hz, is the number of waves that pass by per second. For example, an A note on a violin string vibrates at about 440 Hz (440 vibrations per second).sually frequency is measured in the hertz unit, named in honor of the 19th-century German physicist Heinrich Rudolf Hertz. The hertz measurement, abbreviated Hz, is the number of waves that pass by per second. For example, an A note on a violin string vibrates at about 440 Hz (440 vibrations per second).