what is the si unit of time period
Frequency The SI derived unit of frequency is the hertz (Hz), named after the German physicist Heinrich Hertz. One hertz means that an event repeats once per second. A previous name for this unit was cycles per second (cps). The SI unit for period is the second.
Metrication in the United States Metrication (or metrification) is the process of introducing the International System of Units, also known as SI units or the metric system, to replace a jurisdiction's traditional measuring units. Although all U.S. customary units have been redefined in terms of SI units, as of 2018 the United States is one of only seven countries, including Myanmar (Burma), Liberia,[1] Palau, the Marshall Islands, the Federated States of Micronesia, and Samoa[2] that have not officially adopted the metric system as the primary means of weights and measures.