Frequency German physicist Heinrich Hertz. One hertz means that an event repeats once per second. If a TV has a refresh rate of 1 hertz the TV's screen will change (or refresh) its picture once a second. A previous name for this unit was cycles per second (cps). The SI unit for period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz. As a matter of convenience, longer and slower waves, such as ocean surface waves, tend to be described by wave period rather
Eotvos (unit) Eotvos (unit) The eotvos is a unit of acceleration divided by distance that was used in conjunction with the older centimeter-gram-second system of units (cgs). The eotvos is defined as 1/1,000,000,000 galileos per centimetre. The symbol of the eotvos unit is E. In SI units or in cgs units, 1 eotvos = 10 second. The gravitational gradient of the Earth, that is, the change in the gravitational acceleration vector from one point on the Earth’s surface to another, is customarily measured in units of eotvos. The Earth's gravity gradient is dominated by the component due to Earth's near-spherical shape, which