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Warm Up: August 30, 2013. Ally dropped a delicate glass vase 6 feet from the top of a ladder onto a concrete floor. The glass did not break. Why?. The ladder was 7 feet tall. . Correct HW. 1.3 Measurement.
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Warm Up: August 30, 2013 • Ally dropped a delicate glass vase 6 feet from the top of a ladder onto a concrete floor. The glass did not break. Why?
1.3 Measurement • SI System (Systeme International d’Unites) is an international system of units used by scientists. • It allows scientists in different countries to easily share data and results.
Length • A measure of the distance between two points • SI unit: meter (m) • Instruments used : ruler, meter stick, measuring tape
Time • A measure of the passing of events • SI unit: second (s) • Instruments used : clock, timer
Temperature • A measure of the movement of molecules • SI unit: Kelvin (K) (not °F or °C) • Instrument used: thermometer
Volume • A measure of the amount of space something takes up • SI unit: Liter (L) • Instrument used: graduated cylinder
Mass • The amount of matter present • SI unit: kilogram (kg) (1 kg = 1000 g) A gram is approximately the mass of a paper clip. Instrument: triple beam balance, digital balance
Weight • Weight is not the same as mass. • Weight is force, or push or pull. • Weight depends on gravity and depends on where you are in the universe. • The units for weight are pounds (lb) or Newtons (N). • Instrument: scale, spring scale
Measuring Volume • We measure volume using a graduated cylinder. • They come in a variety of sizes and materials (glass, plastic). • The ones we use measure volume in milliliters (1000 mL = 1 L)
The Meniscus • Many liquids, when placed in a graduated cylinder, will cling to the sides creating a u-shape called a meniscus. • You always use the BOTTOM of the meniscus to make a measurement.
Rainbow Lab • In this lab you will practice using a graduated cylinder to measure volume. • Everyone at your table must make at least one measurement with the graduated cylinder.
Label 6 test tubes in order: A, B, C, D, E & F. • Into test tube A, measure 25 mL of RED liquid. • Into test tube C, measure 17 mL of YELLOW liquid. • Into test tube E, measure 21 mL of BLUE liquid. • Part 2: • From test tube C, measure 4 mL and pour into test tube D. • From test tube E, measure 7 mL and pour into test tube D. Swirl. • From test tube E, measure 4 mL and pour into test tube F. • From test tube A, measure 7 mL and pour into test tube F. Swirl. • From test tube A, measure 8 mL and pour into test tube B. • From test tube C, measure 3 mL and pour into test tube B. Swirl.
Things to think about… • Is there any water or food coloring on your hands or the table? If this liquid was hydrochloric acid, you lost some of your data and may have burned yourself! • Are the volumes in the test tubes what they should be at the end? Double check! Example: Test tube A should have 25 - 7 - 8 = 10 mL Pour the contents on A back in the graduated cylinder and see how you did.
Homework • P. 26 #1a-b & #2a-c • 1.3 Vocabulary Booklet Part I – define: SI, weight, mass, volume, meniscus, density (6 words on p. 16)