Answer:
B. kilogram
Explanation:
When stated in the unit J s, which is equal to kg m2 s1, the kilogram (kg) is defined by considering the fixed numerical value of the Planck constant h to be 6.62607015 1034 when expressed in the unit J s, which is equivalent to kg m2 s1. The United States Prototype Kilogram 20, a platinum-iridium cylinder held at NIST, is the country's principal mass standard. The kilogram was initially known as the Kilogram of the Archives, and it was defined as the mass of one cubic decimeter of water at its greatest density temperature. It was superseded by the International Prototype Kilogram following the International Metric Convention in 1875, which became the unit of mass without reference to the mass of a cubic decimeter of water or the Archives Kilogram. National Prototype Meters and Kilograms were allocated to each country that signed the International Metric Convention. Learn more about the kilogram's history and current definition. The kilogram (kg) is the only SI basic unit whose name and symbol incorporate a prefix for historical reasons. The SI prefix for 1000 or 103 is "kilo." Prefix names and symbols are attached to the unit name "gram," and prefix symbols are attached to the unit symbol "g," to create names and symbols for decimal multiples and submultiples of the unit of mass. Find out more about this historical oddity.
Units of Mass
10 milligrams (mg) = 1 centigrams (cg)
10 centigrams = 1 decigrams (dg) = 100 milligrams
10 decigrams = 1 gram (g)
10 decigrams = 1000 milligrams
10 grams = 1 dekagrams (dag)
10 dekagrams = 1 hectogram (hg)
10 dekagrams = 100 grams
10 hectograms = 1 kilogram (kg)
10 hectograms = 1000 grams
1000 kilograms = 1 megagram (Mg) or 1 metric ton (t)
A body's mass is a measurement of its inertial property, or the amount of stuff it contains. The force imposed on a body by gravity or the force required to maintain it is measured by its weight. On Earth, gravity accelerates a body downward at around 9.8 m/s2. In the context of weights and measurements, weight is frequently used as a synonym for mass. The verb "to weigh," for example, meaning "to ascertain the mass of" or "to have a mass of." Weight should be phased out in favor of mass, and the term mass should be used when mass is indicated. The kilogram is the SI unit of mass (kg). The weight of a body in a given reference frame is defined in science and technology as the force that causes the body to accelerate at the same rate as the local acceleration of free fall in that reference frame. As a result, the newton is the SI unit for the amount weight defined in this way (force) (N).
