Hertz The dimension of the unit hertz is 1/time (1/T). Expressed in base SI units it is 1/second (1/s). In English, "hertz" is also used as the plural form. As an SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 10 Hz), MHz (megahertz, 10 Hz), GHz (gigahertz, 10 Hz) and THz (terahertz, 10 Hz). One hertz simply means "one cycle per second" (typically that which is being counted is a complete cycle); 100 Hz means "one hundred cycles per second", and so on. The unit may be applied to any periodic event—for example, a clock might be
Gram per cubic centimetre Gram per cubic centimetre Gram per cubic centimetre is a unit of density in the CGS system, commonly used in chemistry, defined as mass in grams divided by volume in cubic centimetres. The official SI symbols are g/cm, g·cm, or g cm. It is equivalent to the units gram per millilitre (g/mL) and kilogram per litre (kg/L). The density of water is about 1 g/cm, since the gram was originally defined as the mass of one cubic centimetre of water at its maximum density at 4 °C. 1 g/cm is equivalent to: 1 kg/m = 0.001 g/cm(exactly) 1 lb/ft ≈