SI Units and Measurements PDF

measurement.Of orThe UNITS: BASESI MEASUREMENTS QUANTITY NEASURED standard...

measurement.Of orThe UNITS: BASESI MEASUREMENTS QUANTITY NEASURED standard a S1 substrate amount of SY5TENN volume length(or ntensíty current light electric weight force)(or distance) temperature UNITSANDSI tÉme capacity)(or Mass unit, has for a Chapter every base type unit, (symbol) UNIT SI candela (cd) (mol) "International System."which moleampere(Asecond ) (Kelvin s) (K) newton(N) INTERNATIONALE,standsSI liter(L) gram(g) meter(m) chic! How is French for SYSTEME for 7  Because we want to use SI units to describe both the distance around someone's bicep and the distance arround Farth. we need to be able fo Change Tne size of a unit A a the measurement Scientists devised system of prefiXes Just by switching that multiplies the base unit by factors of 10. Just prefix, an SI unit can be used for the measurements biq and Small: SI PREFIX (symbol) MULTIPLIER giga- (G) 1,000,000,000 mega- (M) 1,000,000 kilo- (k) 1,000 hecto- (h) 100 deca- (da) 10 (base unit] 1 deci- (d) 0.1 centi- (c) 0.01 milli- (m) 0.001 micro- (u) 0.000001 nano- (n) 0.000000001 Ninety-five percent of the world uses SI units as the everyday system of measurement. 38  Mnemonic for YE OLDE SIPrefixes: Great Nighty King Henry Died By Drinking Chunky MON Mik Monday Night. SIUNIT CONVERSIONS Because the SI prefix system is based on powers of 10, it is reallyeasy to convert between units. If you are converting to asmaller unit of measurement, simpls move the decimal point to the right as many places as the difference in place value. If you are converting to a larger unit of measurement, move the decimal point to the left as many places as the difference in place value: 0.001 kilometers 0.0033 kilometers EXANPLES 1meter 3.3 meters 100 centimeters 330centimeters cONMON SENSE TIP Remember to use the best-fitting unit. If you measured the volune of the ocean with the same units you use to measure a glass of milk, the numbers would be very difficult to work with. (The volumeof the ocean should be measured using much larger units.) 39  TYFESoFMEASUREMENT LENGTH: the distance between two points vOLUNE: the amount of space something occupies NASS: the amount of matter in a liquid, When you measure someone's solid, or gas weight, you measure the force they exert on the earth,. WEIGHT: the force exerted by a mass NASS AND WEIGHT ARE NOT THE SAME! Mass is the amount of matter in an object, and weight is the force applied by a mass. Weight relies on gravity (a force), but mass doesn't. For example, the moon has less gravity than the earth, so objects weigh less there than on Earth. Mass always remains the same. Weight changes. DENSITY: the amount of matter in a volume. SINK OR FLOAT? TENPERATURE: how hot Something denser will sinkbelow something that or cold somethinog is. While is less dense. When oil is the SI unit for temperature poured into liquidwater, it is kelvin, most sScientists floats on top of the surface because oilis less dense Use the SI-derived unit, than water. A stone sinks denser Celsius, to measure in water, so it is than water. Water has a temperature. density of approximately must Kelvin doesnt use 1.0, so oil'sdensity and