Objective -> Students will: 1. identify SI units that we will use for various measurements. 2. perform calculations involving SI prefixes.

Transcription

1 Objective -> Students will:. identify SI units that we will use for various measurements. 2. perform calculations involving SI prefixes. Warm-up: Use the english system of units (the same ones we use in the United States) to answer the following:. pound = ounces 2. foot = inches 3. gallon = fluid ounces 4. mile = inches

2 Objective -> Students will:. identify SI units that we will use for various measurements. 2. perform calculations involving SI prefixes. Warm-up: Use the english system of units (the same ones we use in the United States) to answer the following:. pound = 6 ounces 2. foot = 2 inches 3. gallon = 28 fluid ounces 4. mile = 63,36_ inches

3 A small example of the nature of the English system of measurement. English Length Units graph

4 A small example of the nature of the English system of measurement. English Length Units graph I know that you have heard of an inch

5 A small example of the nature of the English system of measurement. English Length Units graph I know that you have heard of an inch, a foot

6 A small example of the nature of the English system of measurement. English Length Units graph I know that you have heard of an inch, a foot, a yard

7 A small example of the nature of the English system of measurement. English Length Units graph I know that you have heard of an inch, a foot, a yard and a mile. But did you know that finger = 7/8 of an inch, and

8 A small example of the nature of the English system of measurement. English Length Units graph I know that you have heard of an inch, a foot, a yard and a mile. But did you know that finger = 7/8 of an inch, and while mile = 5,28 feet on land but on the water nautical mile is 68 feet.

9 Most of you have lived in the United States for your entire life - and you didn t know these things?

10 SI Units (history) The metric system was conceived by a group of scientists (among them, Antoine-Laurent Lavoisier, who is known as the "father of modern chemistry") who had been commissioned by Louis XVI of France to create a unified and rational system of measures. On August 793, the National Convention adopted the new decimal metre with a provisional length as well as the other decimal units with preliminary definitions and terms. On 7 April 795 (Loi du 8 germinal, an III) the terms gramme and kilogramme replaced the former terms gravet (correctly milligrave) and grave. On December 799 (a month after Napoleon's coup d'état), the metric system was definitively adopted in France. Based on the findings of this study, the th CGPM in 954 decided that an international system should be derived from six base units to provide for the measurement of temperature and optical radiation in addition to mechanical and electromagnetic quantities. The six base units that were recommended are the metre, kilogram, second, ampere, degree Kelvin (later renamed the kelvin), and the candela. In 96, the th CGPM named the system the International System of Units, abbreviated SI from the French name: Le Système international d'unités. The seventh base unit, the mole, was added in 97 by the 4th CGPM.

11 SI Units (what you need to know) Quantity length mass time electrical current thermodynamic temperature luminous intensity amount of substance SI Base Units

12 SI Units (what you need to know) Quantity SI Base Units length mass time electrical current thermodynamic temperature luminous intensity amount of substance meter (m) kilogram (kg) second (s) ampere (A) Kelvin (K) candela (cd) mole (mol)

13 SI Units (what you need to know) But did you notice that one seems to be missing?

14 SI Units (what you need to know) But did you notice that one seems to be missing? The official SI unit of VOLUME is the cubic metre (m 3 ).

15 SI Units (what you need to know) But did you notice that one seems to be missing? The official SI unit of VOLUME is the cubic metre (m 3 ). One litre (Liter) is equal to /, cubic metre and is denoted as cubic decimeter (dm 3 ). Liters are most commonly used for items (such as fluids), which are measured by the capacity or size of their container, whereas cubic meters (and derived units) are most commonly used for items measured either by their dimensions or their displacements. The liter is often also used in some calculated measurements, such as density (kg/l), allowing an easy comparison with the density of water.

16 SI Units (what you need to know) Now while the english system that we have grown to know and love has fractions like /4, /2 and 3/4.

17 SI Units (what you need to know) Now while the english system that we have grown to know and love has fractions like /4, /2 and 3/4. The SI Units use fractions equal to /.

18 SI Units (what you need to know) Now while the english system that we have grown to know and love has fractions like /4, /2 and 3/4. The SI Units use fractions equal to /. And of course / can be very easily translated into decimal form.

19 SI Units (what you need to know) Now while the english system that we have grown to know and love has fractions like /4, /2 and 3/4. The SI Units use fractions equal to /. And of course / can be very easily translated into decimal form. And each decimal notation has a prefix to coincide with it.

20 On the larger side: SI Prefixes

21 SI Prefixes On the larger side: tera (T) giga (G) mega (M) kilo (k) hecto (h) deca (da)

22 SI Prefixes On the larger side: tera (T)... 2 giga (G)... 9 mega (M)... 6 kilo (k)... 3 hecto (h) deca (da)

23 SI Prefixes On the larger side: tera (T)... 2 giga (G)... 9 mega (M)... 6 kilo (k)... 3 hecto (h)... 2 deca (da)... On the smaller side:

24 SI Prefixes On the larger side: tera (T)... 2 giga (G)... 9 mega (M)... 6 kilo (k)... 3 hecto (h)... 2 deca (da)... On the smaller side: deci (d) centi (c) milli (m) micro(u) nano (n) pico (p)

25 SI Prefixes On the larger side: tera (T)... 2 giga (G)... 9 mega (M)... 6 kilo (k)... 3 hecto (h)... 2 deca (da)... On the smaller side: deci (d)... - centi (c) milli (m) micro(u) nano (n) pico (p)... -2

26 SI Prefixes So in order it would appear like: T G M k h da unit d c m u n p

27 SI Prefixes T G M k h da unit d c m u n p,,,,,,, So in order it would appear like:,,,,......

28 SI Prefixes T G M k h da unit d c m u n p,,,,,,, So in order it would appear like:,,,,. So it should be obvious that km is much longer than m......

29 SI Prefixes T G M k h da unit d c m u n p,,,,,,, So in order it would appear like:,,,,. So it should be obvious that km is much longer than m.. km =, m....

30 Converting SI Unit Prefixes: Your Turn Directions: Answer the following questions..? cm =. mm 6.? ml =. hl 2.? cm =. km 7.? mg = 5, g 3.? hl = 4. L 8.? dag = 6. g 4.? m =. mm 9.? ms = 5 cs 5.? km =, m.? ml = 4, L These questions should be answered in your composition book.