Metrication in the United States There are no U.S. customary units for electric current, potential difference, or charge since these concepts were developed after the international adoption of metric in science. The metric units ampere, volt, ohm and coulomb are the only units used. The SI term hertz has replaced the term "cycles per second" as a unit of frequency. Energy is often measured in watt hours, BTUs, therms or calories rather than the SI joule. Residential and commercial electrical energy use is metered and billed in kilowatt hours, kW·h, as in most metric countries. Force measurements regularly use the pound instead of the SI
Newton (unit) the thrust of an F100 fighter jet engine are both around 130 kN. One kilonewton, 1 kN, is , or about 100 kg of load. So for example, a platform that shows it is rated at , will safely support a load. Specifications in kilonewtons are common in safety specifications for: Newton (unit) The newton (symbol: N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion. See below for the conversion factors. "One newton is the force needed