Second sound travels about 343 meters in one second in air; light takes 1.3 seconds to reach Earth from the surface of the Moon, a distance of 384,400 kilometers. A second is part of other units, such as frequency measured in hertz (inverse seconds or second), speed (meters per second) and acceleration (meters per second squared). The metric system unit becquerel, a measure of radioactive decay, is measured in inverse seconds. The meter is defined in terms of the speed of light and the second; definitions of the metric base units ampere and candela also depend on the second. Of the
Kilogram-force per square centimetre SI units, the unit is converted to the SI derived unit pascal (Pa), which is defined as one newton per square metre (N/m). A newton is equal to a kg·m/s, and a kilogram-force is 9.80665 newtons, meaning that 1 kgf/cm equals 98.0665 kilopascals (kPa). In some older publications, kilogram-force per square centimetre is abbreviated ksc instead of kg/cm. All the Russian origin gauges are indicating pressure in Kgf/cm2 and are calibrated annually. Kilogram-force per square centimetre A kilogram-force per centimetre square (kgf/cm), often just kilogram per square centimetre (kg/cm), or kilopond per centimetre square is a deprecated unit of pressure