Pflugerville ISD - August Pflugerville Independent School District Integrated Physics & Chemistry Measurement

Pflugerville ISD - August Quantitative and Qualitative Observations What do YOU think the difference is?

Pflugerville ISD - August ) What is a system of measurement ? 2) Metric system- AKA International system, and SI (Systeme International d'Unites) English system- AKA British system, customary system & “our” system 3, 4, 5, 6) METRIC!!!!!!

Pflugerville ISD - August Base Metric Units Meters measure length Kilograms measure mass Seconds measures time Kelvin measures temperature Ampere measures current Lumens measures light intensity Moles measures the amount of a substance

Pflugerville ISD - August Metric Prefixes Kilo = 1000 Hecto = 100 Deka = 10 Deci = 1/10 Centi = 1/100 Milli = 1/1000

Pflugerville ISD - August Other Derived Metric Units (from basic 7) Volume is length x width x height measured in centimeters cubed or millilters Temperature is measured in degrees celsius or centigrade ( o C) Heat is measured in calories (cal) or joules (J) Weight is measured in newtons (N)

Pflugerville ISD - August How Big?  A meter is about 39 inches  A kilometer is 0.6 mile  A centimeter is about the width of your little finger  A gram is about the mass of a paper clip  A kilogram is 2.2 pounds  You drink 2 liters of pop  See handout for other prefixes

Pflugerville ISD - August Tools for Measurement Meterstick Balance (triple beam and digital) Graduated Cylinder Stopwatch Thermometer Multimeter Photometer

Pflugerville ISD - August Graduated Cylinder Measurement Volume is measured using a graduated cylinder. When reading a graduated cylinder, read the bottom of the meniscus.

Pflugerville ISD - August Insert Slides on Dimensional Analysis From Bill Anderson, HHS

Pflugerville ISD - August K H D O D C M To change from one metric unit to another, we simply multiply by a conversion factor. For example: 25.4 km = _____________ cm? 25.4 km x 1000cm/1km = 2,540,000 cm

Pflugerville ISD - August Scientific Notation Rules: 1 digit before the decimal point Multiply the number by a power of 10 Example: Write 34,000 in scientific notation. Solution: 3.4 x 10 4

Pflugerville ISD - August Write the following in scientific notation: 4,100,000 = _______________ 345,600,000,000 = _________ = ________________ =____________ O.00305= ____________ 4.1 x x x x x 10 -3

Pflugerville ISD - August Write the following in standard form: 4.67 x 10 3 =__________________ x 10 5 = _________________ x = ________________ 4 x = ___________________ 1 x = __________________ ,000,000,000

Pflugerville ISD - August Density of Water One milliliter of water Has a mass of 1 gram Density = Mass ÷ Volume Calculate the density of water 1g ÷ 1mL = 1g/mL

Pflugerville ISD - August Measuring Water If you wanted to measure 25 mL of water, what instrument would you use?

Pflugerville ISD - August Measuring Water If you wanted to measure 25 grams of water, what 2 instruments could you use?

Pflugerville ISD - August Accuracy vs. Precision ACCURACY "capable of providing a correct reading or measurement.” A measurement is accurate if it correctly reflects the size of the thing being measured. PRECISION "exact, as in performance, execution, or amount.” It means repeatable, reliable, getting the same measurement each time.

Pflugerville ISD - August Try This On-line Activity asurement/session2/part_c/accuracy.html

Pflugerville ISD - August Measuring volume of a solid by water displacement

Pflugerville ISD - August One cubic centimeter = One milliliter This cube’s sides are each 3 cm. What is the volume of the cube? Using water displacement, how many milliliters do you expect the water to raise when the cube is lowered?

Pflugerville ISD - August That’s all folks! Time to try some on your own!