Do Now NOTHING! Someone 6 foot tall and 182 centimeters? Someone who is 182 lbs, 13 stone, or 82.5 kg? 1.5 minutes and 90 seconds?

Transcription

1 Do Now q What is the difference between: Someone 6 foot tall and 182 centimeters? Someone who is 182 lbs, 13 stone, or 82.5 kg? 1.5 minutes and 90 seconds? NOTHING!

2 Concepts You Should Know 1. Metric System 2. Metric Base Units for Length, Mass, Time & Volume 3. Metric Prefixes-Mega, Kilo, Deci, Centi, Milli, Micro, Nano & Pico 4. Density 5. Temperature Scales-Celsius (Centigrade) and Kelvin 6. Mass & Weight

3 Skills You Should Master 1. Converting Between Celsius and Kelvin 2. Interconverting between Mass, Volume, & Density

4 Unit 1: MEASUREMENTS & PROBLEM SOLVING 3 SCIENTIFIC MEASUREMENTS 3.3 The Metric System

5 The SI System aka Metric System 1 Scientists use a universal way to describe and measure matter: the International System of Units (SI Units). -adopted in 1960 REFRESHER: What is matter?

6 The SI System Base Units 2 The SI system uses 7 base units of measurement. SI Base Units Quantity SI Base Unit Symbol Length meter m Mass kilogram kg Temperature kelvin K Time second s Amount of substance mole mol Luminous intensity candela cd Electric current Ampere A

7 Derived SI Units 3 Derived SI base Units There are two derived SI units: Volume and Density Derived SI Units Quantity SI Unit Symbol Volume liter L Density grams/cubic centimeter g/cm 3 How many SI base units do we have?

8 Making the SI System Better Your height 1.8 meter Size of a Carbon atom The Earth-Moon distance m 384,400,000 m

9 The SI System Metric Prefixes 4 The SI system uses metric prefixes for expressing very large and very small numbers. Commonly Used Metric Prefixes Prefix Symbol Meaning Factor mega M 1million times larger than the unit it precedes 10 6 kilo K 1000 times larger than the unit it precedes 10 3 These - prefixes m Base Unit are common for all S.I. 1 units deci d 10 times smaller than the unit it precedes 10-1 centi c 100 times smaller than the unit it precedes 10-2 milli m 1000 times smaller than the unit it precedes 10-3 micro 1milllion times smaller than the unit it precedes 10-6 nano n 1billion times smaller than the unit it precedes 10-9 pico p 1trillion times smaller than the unit it precedes 10-12

10 Using SI System Prefixes Your height 1.8 m (meter) Carbon atom m 70 pm (picometer) The Earth-Moon distance 384,400,000 meter 384 Mm (megameter)

11 Metric Units of Length Metric Units of Length Unit Symbol Relationship Examples Kilometer km 1 km = 10 3 m Length of about 5 city blocks Decameter Dm 1 Dm = 10 m Length of a room Meter m base unit Height of a human Decimeter d 10 1 dm = 1m Length of your hand Centimeter c 10 2 cm = 1m diameter of a penny Millimeter m 10 3 mm = 1m Length of a small fire ant Micrometer 10 6 µm = 1m Thickness of a bacterial cell Nanometer n 10 9 nm = 1m Thickness of a DNA molecule (2 nm) Picometer p pm = 1m Size of a Carbon atom

12 NANO MICRO MILLI CENTI DECI BASE UNIT KILO MEGA 0.5 µm x 2 µm 2 mm x 6 mm 1.9 cm dia. 2.0 dm 2.74 Km molecule of glucose (1 nm) San Deigo-El Paso 1.01 Mm 1.6 m

13 Metric Units of Mass Metric Units of Mass Unit Symbol Relationship Examples Kilogram kg base unit small textbook 1kg Gram g 10 3 g = 1kg dollar bill 1g Milligram mg 10 3 mg = 1g ten grains of salt 1mg Microgram µg 10 6 µg = 1g particles of baking powder 1µg Nanogram ng 10 9 µg = 1g Picogram pg µg = 1g

14 Metric Units of Time Metric Units of Mass Unit Symbol Relationship Examples kilosecond ks 1 ks = 1000s hectosecond hs 1 hs = 100 s decasecond ds 1 ds = 10 s second s base unit Humans can sense passage of1s millisecond ms 10 3 s = 1s Video refresh rate ~ 30 milliseconds microsecond µs 10 6 µs = 1s nanosecond ns 10 9 ns = 1s picosecond ng ps = 1s femtosecond fs fs = 1s

15 Volume 6 Volume is the amount of space occupied by an object. Volume = 10 cm x 10 cm x 10 cm = 1000 cm 3 = 1L (base unit)

16 Metric Units of Volume Metric Units of Volume Unit Symbol Relationship Examples Liter L base unit 1 quart of milk 1L Milliliter Cubic centimeter ml cm 3 1cm 3 = 1ml 10 3 ml = 10 3 cm 3 = 1L 20 drops of water 1 ml cube of sugar 1 cm 3 Microliter µl 10 3 µl = 1 L crystal of table salt 1µL

17 Density 7 Density Density is the ratio of the mass of an object to its volume. Density = mass volume SI unit of density is g/cm 3

18 Density

19 Density Problems What is the density of an object having a mass of 8.0 g and a volume of 25 cm?

20 Temperature Scales 8 Scientists use two equivalent units of temperature: the degree Celsius and the kelvin.

21 Temperature Problems What is the temperature 128 K expressed in degrees Celsius?

22 Temperature Problems What is the boiling point of water in kelvins?

23 Temperature Problems What is the temperature 34 0 C expressed in kelvins?

24 3.3 The S. I. Metric System Notes The S. I. Base Units for Length is meter (m) Mass is Kilogram (kg) Time is second (s) Temperature is Kelvin (K) Amount of substance is mole (mol) Luminous intensity is candela (cd) Electric current is ampere (A) The S. I. Base Units for Derived Units Volume is Liter (L) Density is g/cm 3

25 3.3 The S. I. Metric System Notes Density = Mass (g/cm 3 ) Volume Temperature is measured in Celsius (a.k.a centigrade) and Kelvin 0 C = K 273 K = 0 C + 273

26 3.3 SI Metric System Exit Ticket 1. Write the S.I. units for a. body temperature b. liquid volume c. height d. body mass 2. A copper penny has a mass of 3.1g and a density of 0.35 cm 3. What is the density of the copper penny? 3. Write the symbols for the following a. millisecond b. centimeter c. kilogram 4. Convert 0K to 0 C.