The International System of Units (SI)
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Appendix A: Symbols and Prefixes
Appendix A: Symbols and Prefixes (Appendix A last revised November 2020) This appendix of the Author's Kit provides recommendations on prefixes, unit symbols and abbreviations, and factors for conversion into units of the International System. Prefixes Recommended prefixes indicating decimal multiples or submultiples of units and their symbols are as follows: Multiple Prefix Abbreviation 1024 yotta Y 1021 zetta Z 1018 exa E 1015 peta P 1012 tera T 109 giga G 106 mega M 103 kilo k 102 hecto h 10 deka da 10-1 deci d 10-2 centi c 10-3 milli m 10-6 micro μ 10-9 nano n 10-12 pico p 10-15 femto f 10-18 atto a 10-21 zepto z 10-24 yocto y Avoid using compound prefixes, such as micromicro for pico and kilomega for giga. The abbreviation of a prefix is considered to be combined with the abbreviation/symbol to which it is directly attached, forming with it a new unit symbol, which can be raised to a positive or negative power and which can be combined with other unit abbreviations/symbols to form abbreviations/symbols for compound units. For example: 1 cm3 = (10-2 m)3 = 10-6 m3 1 μs-1 = (10-6 s)-1 = 106 s-1 1 mm2/s = (10-3 m)2/s = 10-6 m2/s Abbreviations and Symbols Whenever possible, avoid using abbreviations and symbols in paragraph text; however, when it is deemed necessary to use such, define all but the most common at first use. The following is a recommended list of abbreviations/symbols for some important units. -
Quantity Symbol Value One Astronomical Unit 1 AU 1.50 × 10
Quantity Symbol Value One Astronomical Unit 1 AU 1:50 × 1011 m Speed of Light c 3:0 × 108 m=s One parsec 1 pc 3.26 Light Years One year 1 y ' π × 107 s One Light Year 1 ly 9:5 × 1015 m 6 Radius of Earth RE 6:4 × 10 m Radius of Sun R 6:95 × 108 m Gravitational Constant G 6:67 × 10−11m3=(kg s3) Part I. 1. Describe qualitatively the funny way that the planets move in the sky relative to the stars. Give a qualitative explanation as to why they move this way. 2. Draw a set of pictures approximately to scale showing the sun, the earth, the moon, α-centauri, and the milky way and the spacing between these objects. Give an ap- proximate size for all the objects you draw (for example example next to the moon put Rmoon ∼ 1700 km) and the distances between the objects that you draw. Indicate many times is one picture magnified relative to another. Important: More important than the size of these objects is the relative distance between these objects. Thus for instance you may wish to show the sun and the earth on the same graph, with the circles for the sun and the earth having the correct ratios relative to to the spacing between the sun and the earth. 3. A common unit of distance in Astronomy is a parsec. 1 pc ' 3:1 × 1016m ' 3:3 ly (a) Explain how such a curious unit of measure came to be defined. Why is it called parsec? (b) What is the distance to the nearest stars and how was this distance measured? 4. -
Calculating Growing Degree Days by Jim Nugent District Horticulturist Michigan State University
Calculating Growing Degree Days By Jim Nugent District Horticulturist Michigan State University Are you calculating degree day accumulations and finding your values don't match the values being reported by MSU or your neighbor's electronic data collection unit? There is a logical reason! Three different methods are used to calculate degree days; i.e., 1) Averaging Method; 2) Baskerville-Emin (BE) Method; and 3) Electronic Real-time Data Collection. All methods attempt to calculate the heat accumulation above a minimum threshold temperature, often referred to the base temperature. Once both the daily maximum and minimum temperatures get above the minimum threshold temperature, (i.e., base temperature of 42degrees, 50degrees or whatever other base temperature of interest) then all methods are fairly comparable. However, differences do occur and these are accentuated in an exceptionally long period of cool spring temperatures, such as we experienced this year. Let me briefly explain: 1. Averaging Method: Easy to calculate Degree Days(DD) = Average daily temp. - Base Temp. = (max. + min.) / 2 - Base temp. If answer is negative, assume 0. Example: Calculate DD Base 50 given 65 degrees max. and 40 degrees min. Avg. = (65 + 40) / 2 = 52.5 degrees DD base 50 = 52.5 - 50 = 2.5 degrees. But look what happens given a maximum of 60 degrees and a minimum of 35 degrees: Avg. = (60 + 35) / 2 = 47.5 DD base 50 = 47.5 - 50 = -2.5 = 0 degrees. The maximum temperature was higher than the base of 50° , but no degree days were accumulated. A grower called about the first of June reporting only about 40% of the DD50 that we have recorded. -
8.1 Basic Terms & Conversions in the Metric System 1/1000 X Base Unit M
___________________________________ 8.1 Basic Terms & Conversions in the Metric System ___________________________________ Basic Units of Measurement: •Meter (m) used to measure length. A little longer than a yard. ___________________________________ ___________________________________ •Kilogram (kg) used to measure mass. A little more than 2 pounds. ___________________________________ •Liter (l) used to measure volume. A little more than a quart. •Celsius (°C) used to measure temperature. ___________________________________ ___________________________________ ch. 8 Angel & Porter (6th ed.) 1 The metric system is based on powers of 10 (the decimal system). ___________________________________ Prefix Symbol Meaning ___________________________________ kilo k 1000 x base unit ___________________________________ hecto h 100 x base unit deka da 10 x base unit ___________________________________ ——— ——— base unit deci d 1/10 x base unit ___________________________________ centi c 1/100 x base unit milli m 1/1000 x base unit ___________________________________ ___________________________________ ch. 8 Angel & Porter (6th ed.) 2 ___________________________________ Changing Units within the Metric System 1. To change from a smaller unit to a larger unit, move the ___________________________________ decimal point in the original quantity one place to the for each larger unit of measurement until you obtain the desired unit of measurement. ___________________________________ 2. To change form a larger unit to a smaller unit, move the decimal point -
Conversion Table Cubic Meter to Metric Ton
Conversion Table Cubic Meter To Metric Ton Ensorcelled Nathan still cokes: masked and unstinting Amery breast-feeds quite wherein but cribbling her miscegenations east-by-north. Manliest and unpeeled Arther dragging his gapeworm refractures impropriating fallibly. Hilarious Darren taboo his depiction disanoints introrsely. Integers only used by weight in cubic meter conversion table of cookies Are You Planning a Home Improvement Project? Click here a stop to gauge the corresponding answer. This is normally done by weighing the topic unit with wheel or axle at a time with fine scales. Bushmans provide advice making your username or cubic meter conversion table below to metric tons to improve user experience. How soon you calculate cubic Litres? Cubic meters to tons water Conversion calculator formula. Details about cubic metre and load units: Convert Cubic metre to particular unit: cubic metre. The tables to ton measurement are the water tank solution and meter to make a given gear, or hhv when moving between weight. If we now have to metric. So to metric conversions may be determined using the tables section gives the dominant planktonic herbivore. Use this to metric tons to advice from a force per degree rankine. Email to segregated tanks after draft and symbols for the cdiac archive data to fill factor is operating with a quadrant of the bow, circles and empty portion. Wiktionary, the net dictionary. Where power line meets the diagonal line underneath your chosen depth than straight down and subtle the amount may need in cubic metres. CFI requirement for the Committee approved electricity purchases. Convert metric tons to cubic meters & vice versa. -
Units, Conversations, and Scaling Giving Numbers Meaning and Context Author: Meagan White; Sean S
Units, Conversations, and Scaling Giving numbers meaning and context Author: Meagan White; Sean S. Lindsay Version 1.3 created August 2019 Learning Goals In this lab, students will • Learn about the metric system • Learn about the units used in science and astronomy • Learn about the units used to measure angles • Learn the two sky coordinate systems used by astronomers • Learn how to perform unit conversions • Learn how to use a spreadsheet for repeated calculations • Measure lengths to collect data used in next week’s lab: Scienctific Measurement Materials • Calculator • Microsoft Excel • String as a crude length measurement tool Pre-lab Questions 1. What is the celestial analog of latitude and longitude? 2. What quantity do the following metric prefixes indicate: Giga-, Mega-, kilo-, centi-, milli-, µicro-, and nano? 3. How many degrees is a Right Ascension “hour”; How many degrees are in an arcmin? Arcsec? 4. Use the “train-track” method to convert 20 ft to inches. 1. Background In any science class, including astronomy, there are important skills and concepts that students will need to use and understand before engaging in experiments and other lab exercises. A broad list of fundamental skills developed in today’s exercise includes: • Scientific units used throughout the international science community, as well as units specific to astronomy. • Unit conversion methods to convert between units for calculations, communication, and conceptualization. • Angular measurements and their use in astronomy. How they are measured, and the angular measurements specific to astronomy. This is important for astronomers coordinate systems, i.e., equatorial coordinates on the celestial sphere. • Familiarity with spreadsheet programs, such as Microsoft Excel, Google Sheets, or OpenOffice. -
Lesson 1: Length English Vs
Lesson 1: Length English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer B. 1 yard or 1 meter C. 1 inch or 1 centimeter English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer 1 mile B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer 1 mile B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers 1 yard = 0.9444 meters English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer 1 mile B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers 1 inch = 2.54 centimeters 1 yard = 0.9444 meters Metric Units The basic unit of length in the metric system in the meter and is represented by a lowercase m. Standard: The distance traveled by light in absolute vacuum in 1∕299,792,458 of a second. Metric Units 1 Kilometer (km) = 1000 meters 1 Meter = 100 Centimeters (cm) 1 Meter = 1000 Millimeters (mm) Which is larger? A. 1 meter or 105 centimeters C. 12 centimeters or 102 millimeters B. 4 kilometers or 4400 meters D. 1200 millimeters or 1 meter Measuring Length How many millimeters are in 1 centimeter? 1 centimeter = 10 millimeters What is the length of the line in centimeters? _______cm What is the length of the line in millimeters? _______mm What is the length of the line to the nearest centimeter? ________cm HINT: Round to the nearest centimeter – no decimals. -
Binary Operator
Table of Contents Teaching and Learning The Metric System Unit 1 1 - Suggested Teaching Sequence 1 - Objectives 1 - Rules of Notation 1 - Metric Units, Symbols, and Referents 2 - Metric Prefixes 2 - Linear Measurement Activities 3 - Area Measurement Activities 5 - Volume Measurement Activities 7 - Mass (Weight) Measurement Activities 9 - Temperature Measurement Activities 11 Unit 2 12 - Objectives 12 - Suggested Teaching Sequence 12 - Metrics in this Occupation 12 - Metric Units For Binary Operation 13 - Trying Out Metric Units 14 - Binding With Metrics 15 Unit 3 16 - Objective 16 - Suggested Teaching Sequence 16 - Metric-Metric Equivalents 16 - Changing Units at Work 18 Unit 4 19 - Objective 19 - Suggested Teaching Sequence 19 - Selecting and Using Metric Instruments, Tools and Devices 19 - Which Tools for the Job? 20 - Measuring Up in Binary Operations 20 Unit 5 21 - Objective 21 - Suggested Teaching Sequence 21 - Metric-Customary Equivalents 21 - Conversion Tables 22 - Any Way You Want It 23 Testing Metric Abilities 24 Answers to Exercises and Test 25 Tools and Devices List References TEACHING AND LEARNING THE METRIC SYSTEM Thi.s metric instructional package was designed to meet job-related Unit 2 provides the metric terms which are used in this occupation metric measurement needs of students. To use this package students and gives experience with occupational measurement tasks. should already know the occupational terminology, measurement terms, and tools currently in use. These materials were prepared with Unit 3 focuses on job-related metric equivalents and their relation the help of experienced vocational teachers, reviewed by experts, tested ships. in classrooms in different parts of the United States, and revised before distribution. -
Having Regard to the Opinion of the European Chapter 1 of the Annex Binding Within Five Years of Parliament1 ; the Date of Entry Into Force of This Directive
878 Official Journal of the European Communities 29.10.71 Official Journal of the European Communities No L 243/29 COUNCIL DIRECTIVE of 18 October 1971 on the approximation of the laws of the Member States relating to units of measurement (71/354/EEC ) THE COUNCIL OF THE EUROPEAN COMMUNITIES, particular their names, symbols and use are not identical in the Member countries ; Having regard to the Treaty establishing the European Economic Community, and in particular HAS ADOPTED THIS DIRECTIVE : Article 100 thereof; Article 1 Having regard to the proposal from the Commission ; 1 . Member States shall make the provisions of Having regard to the Opinion of the European Chapter 1 of the Annex binding within five years of Parliament1 ; the date of entry into force of this Directive. 2 . Member States shall, with effect from 31 Having regard to the Opinion of the Economic and December 1977 at the latest, prohibit the use of the Social Committee2; units of measurement listed in Chapter III of the Annex. Whereas - the laws which regulate the use of units of measurement in the Member States differ from one 3 . The units of measurement temporarily" retained Member State to another and therefore hinder trade ; in accordance with the provisions of Chapter II or whereas application of the rules relating to measuring Chapter III of the Annex may not be brought into instruments is closely linked to the use of units of compulsory use by the Member States where they ' are measurement in the metrological system ; whereas, in not authorised at the date when this Directive enters into force . -
Electric Units and Standards
DEPARTMENT OF COMMERCE OF THE Bureau of Standards S. W. STRATTON, Director No. 60 ELECTRIC UNITS AND STANDARDS list Edition 1 Issued September 25. 1916 WASHINGTON GOVERNMENT PRINTING OFFICE DEPARTMENT OF COMMERCE Circular OF THE Bureau of Standards S. W. STRATTON, Director No. 60 ELECTRIC UNITS AND STANDARDS [1st Edition] Issued September 25, 1916 WASHINGTON GOVERNMENT PRINTING OFFICE 1916 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 15 CENTS PER COPY A complete list of the Bureau’s publications may be obtained free of charge on application to the Bureau of Standards, Washington, D. C. ELECTRIC UNITS AND STANDARDS CONTENTS Page I. The systems of units 4 1. Units and standards in general 4 2. The electrostatic and electromagnetic systems 8 () The numerically different systems of units 12 () Gaussian systems, and ratios of the units 13 “ ’ (c) Practical ’ electromagnetic units 15 3. The international electric units 16 II. Evolution of present system of concrete standards 18 1. Early electric standards 18 2. Basis of present laws 22 3. Progress since 1893 24 III. Units and standards of the principal electric quantities 29 1. Resistance 29 () International ohm 29 Definition 29 Mercury standards 30 Secondary standards 31 () Resistance standards in practice 31 (c) Absolute ohm 32 2. Current 33 (a) International ampere 33 Definition 34 The silver voltameter 35 ( b ) Resistance standards used in current measurement 36 (c) Absolute ampere 37 3. Electromotive force 38 (a) International volt 38 Definition 39 Weston normal cell 39 (b) Portable Weston cells 41 (c) Absolute and semiabsolute volt 42 4. -
About SI Units
Units SI units: International system of units (French: “SI” means “Système Internationale”) The seven SI base units are: Mass: kg Defined by the prototype “standard kilogram” located in Paris. The standard kilogram is made of Pt metal. Length: m Originally defined by the prototype “standard meter” located in Paris. Then defined as 1,650,763.73 wavelengths of the orange-red radiation of Krypton86 under certain specified conditions. (Official definition: The distance traveled by light in vacuum during a time interval of 1 / 299 792 458 of a second) Time: s The second is defined as the duration of a certain number of oscillations of radiation coming from Cs atoms. (Official definition: The second is the duration of 9,192,631,770 periods of the radiation of the hyperfine- level transition of the ground state of the Cs133 atom) Current: A Defined as the current that causes a certain force between two parallel wires. (Official definition: The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 Newton per meter of length. Temperature: K One percent of the temperature difference between boiling point and freezing point of water. (Official definition: The Kelvin, unit of thermodynamic temperature, is the fraction 1 / 273.16 of the thermodynamic temperature of the triple point of water. Amount of substance: mol The amount of a substance that contains Avogadro’s number NAvo = 6.0221 × 1023 of atoms or molecules. -
Distances in the Solar System Are Often Measured in Astronomical Units (AU). One Astronomical Unit Is Defined As the Distance from Earth to the Sun
Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km (93 million miles). Table below shows the distance from the Sun to each planet in AU. The table shows how long it takes each planet to spin on its axis. It also shows how long it takes each planet to complete an orbit. Notice how slowly Venus rotates! A day on Venus is actually longer than a year on Venus! Distances to the Planets and Properties of Orbits Relative to Earth's Orbit Average Distance Length of Day (In Earth Length of Year (In Earth Planet from Sun (AU) Days) Years) Mercury 0.39 AU 56.84 days 0.24 years Venus 0.72 243.02 0.62 Earth 1.00 1.00 1.00 Mars 1.52 1.03 1.88 Jupiter 5.20 0.41 11.86 Saturn 9.54 0.43 29.46 Uranus 19.22 0.72 84.01 Neptune 30.06 0.67 164.8 The Role of Gravity Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a strong.