Hertz radians per second. Thus a disc rotating at 60 revolutions per minute (rpm) is said to be rotating at either 2 rad/s "or" 1 Hz, where the former measures the angular velocity and the latter reflects the number of "complete" revolutions per second. The conversion between a frequency "f" measured in hertz and an angular velocity "ω" measured in radians per second is The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1930. It was adopted by
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