1 / 30

Measurement & Calculation

Measurement & Calculation. An Introduction. Scientific Inquiry: What it is & What it is not!. Scientific Thinking Process. Applying Using knowledge to solve complex problems; inventing. Inferring Predicting patterns based on data formulating models; theorizing.

shelly
Download Presentation

Measurement & Calculation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measurement & Calculation An Introduction Scientific Inquiry: What it is & What it is not!

  2. Scientific Thinking Process ApplyingUsing knowledge to solve complex problems; inventing InferringPredicting patterns based on data formulating models; theorizing RelatingCause and effect relationships; space/time relationships; controlled experimentation OrganizingCategorizing, grouping, classifying Ordering: seriating and sequencing ComparingSensory comparisons, relative position comparisons; measurement (linear, volume, mass, quantity, temperature) CommunicatingSilent, oral, written, pictorial Observing Seeing, hearing, feeling, tasting, smelling

  3. Scientific Inquiry Form Hypothesis Gather data-observable; measurable; replicable Design experiment Use technology to investigate-weigh, calculate Analyze and describe data-statistical; graph Evaluate accuracy and precision of data Revise scientific explanation or model- using logic and evidence Communicate and defend

  4. Example- Which Shampoo to use? • Question: Is Suave shampoo the “best?” Hypothesis: Which shampoo cleans the best? (leaves least residue) Gather data: Buy shampoos Design experiment: Determine test-hair or fabric or glass Set up & perform experiment: Use 3 glasses; Wash- #1-with water only #2-Suave #3-Adidas Evaluate: Compare glassware immediately; later; Retest-compare Communicate: Tell others! Analyze was the difference significant

  5. Scientific Method: logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data. Hypothesis: testable statement which makes predictions Model: Physical object that explains how a phenomena occurs and how data or events are related. Theory: Broad generalization that explains a body of facts or phenomena

  6. Scientific Inquiry Earth is center of universe Claudis Ptolemy Sun is center of Universe Nicolas Copernicus A.D. 150 1543

  7. Psuedoscience • Fake science that has no tests for its validity. Phrenology Astrology-Horoscopes Superstition

  8. Which are testable hypotheses? • 1. Topeka West football team is #1 in 5A Division. • 2. The Topeka West band has the best uniforms. • 3. Taco John’s tacos are the best price in Topeka. • 4. American Eagle jeans fit better than Old Navy jeans. • 5. Nicolas Coperinus was first to publish a heliocentric model • for the universe. 6. Meterologists use weather balloons to study the upper atmosphere. Which are scientific laws/principle? Scientific Law: A general hypothesis/statement about the relationship of natural quantities that has been proven over & over again. Matter is neither created nor destroyed; simply interchanged. Every object remains at rest or in at continual motion until another force is acted on it. The position of the Milky Way Galaxy will remain constant.

  9. Measurement Mania! • Does size matter REALLY?!! What items require exact measurement to you? Quantity: Something that has magnitude, size, or amount

  10. SI Measurement:Le Systeme International d’Unites • Base Units • Length- m meter m • Mass kg kilogram kg • Time t second s • Temperature T Kelvin K • Amount of substance n mole mol • Electric current l ampere A • Luminous intensity Iv candela cd

  11. SI Prefixes

  12. Can you see estimate these sizes? How many meters tall is Michael Beasley? How many centimeters tall is Beasley? Can you convert between units? He is 6’8” tall. There are 39” in a meter. There are 12” in a foot. The answer: He is 80” tall which is 2.02 meters. How many cm?

  13. Weight vs. Mass • What the difference between weight & mass? Picture of Earth & Moon as seen from Mars! Weight- measure of the gravitational pull on matter Mass- measure of the quantity of matter in a substance

  14. Derived SI Units • Derived units are combinations of the SI base quantities. • Volume is the amount of space occupied by a substance. • Some combination units have their own name: • Heat measurement: • Joule= force x length newton * m • Pressure measurement: • Pascal=Pa= force/area • newton/m2 = kg/m * s2

  15. Derived units- great for applications! Quantity Symbol Unit Derivation Area A m2 length x width Volume V m3 length x width x height Density D kg/m3 mass/volume Molar mass M kg/mol mass/amt of sub. Concentration c mol/L amt of sub./volume Molar volume V m3/mol volume/amt of sub. Energy E Joule force x length Note: mol = mole

  16. Breakdown of derived units Area= length x width 2 cm x 8 cm = 16 cm 2 2 cm 8 cm 6 m 2 m Volume = length x width x height 4m x 2m x 6m= 48 m3 4 m 6 m 2 m 4 m 24 kg = 0.5 kg/m3 4m x 2m x 6m Density = mass/volume 24 kg

  17. Molar mass = mass amt. of sub. 8 kg = 2 kg 4 mol mol 8 kg 4 moles of NaCl Concentration= Amt. of sub volume 3 mol = 3 mol 1 L L 3 moles Co 1000 ml 0.4 moles caffeine Molar Volume= volume amt of substance 0.4 L = 1 L 0.4 mol mol 0.4 L

  18. Density – “It’s your destiny!” Density = Mass Volume Volume= MassMass = (Density) * (Volume) Density http://www.youtube.com/watch?v=14nahP_FVnM

  19. What are things you convert daily?

  20. Conversion Units 1 dozen donuts = 12 donuts If I had 3 dozen donuts, how many donuts do I have? 3 dozen| 12 donuts = 36 donuts 1 dozen If I had 48 donuts, how many dozen donuts do I have? 48 donuts|1 dozen=4 dozen donuts 12 donuts

  21. Conversion Factors • A conversion factor is a ratio derived from the equality between two different units that can be used to convert from one unit to the other. • Always go back to the units you know well • Use LOGIC! 1 m = 100 cm = 0.001 km How many km is it to KU if you are 7800 m away? 1 L = 1000 ml = 100 cl How many ml are in 6.2 L of Mt. Dew? 1 kg = 1000 g = 1,000,000 mg How many g are in 500,000 mg? 7.8km 6200 ml 500 g

  22. Accuracy & Precision • Accuracy refers to the closeness of measurements to the correct or accepted value of the quantity measured. • Precision refers to the closeness of a set of measurements of the same quantity made in the same way.

  23. What was your error in your last prediction? Name some predictions- Percent error is calculated by subtracting the e xperimental value from the accepted value, dividing the difference by the accepted value, and then multiplying by 100. Percent Error = Valueaccepted – Valueexperimentalx 100 Valueaccepted

  24. Significant Figures Significant Figures- numbers in a measurement consist of all the digits known with certainty plus one final digit, which is somewhat uncertain or is estimated. http://www.youtube.com/watch?v=9PeVHnjqbBc Rules on Significant Figures- Non-zero numbers are significant (83.45) Captured zeros are significant. (bordered by nonzero numbers- like 703) Trailing zeros are significant IF there is a decimal (2.60; 400; 401.) Leading zeros are never significant (00.016)

  25. Identify the number of significant figures: 1) 3.0800 2) 0.00418 3) 7.09 x 10¯5 4) 91,600 5) 0.003005 6) 3.200 x 109 7) 250 8) 780,000,000 9) 0.0101 10) 0.00800 1)5 2)3 3)3 4)3 5)4 6)4 7)2 8)2 9)3 10)3 11) 13.01 + 10.1 = a. 23 b. 23.1 c. 23.11 12) 20.5 – 6.33 = a. 15 b. 14.2 c. 14.23 13) 22.1 + 14.2 = a. 30 b. 36 c. 36.3 14) 1.5 x 2 = a. 3 b. 3.0 c. 3.00 11) b. 12)b 13)c 14)a

  26. Sig Figs in action! Addition & Subtraction Multiplication & Division • When adding or subtracting decimals, the answer must have the same number of digits to the right of the decimal point as there are in the measurement having the fewest digits to the right of the decimal point. • Ex. 13.55 – 4.3 = 9.25 = 9.3 (round) • Whole numbers should be rounded so that the answer’s final digit should be rounded the same as that of the leftmost uncertain digit regardless of the number of places. • http://www.youtube.com/watch?v=5UjwJ9PIUvE&feature=related First determine the significant figures of the numbers of the problem. The least significant figure determines the number of significant figures in the product or quotient. Ex. 237/6 = 39.5 = 40

  27. Significant Figures Practice • Addition/subtraction- when adding or subtracting decimals, the answer must have the same places as the least significant figure. You cannot produce a more accurate number than you started! Ex. 6.32 g 8.0 g + 1.2 g - 7.2 g • Multiplication/division • The answer can have no more significant figures than are in the measurement with the fewest number of significant figures. • Ex. 1.10 mm x 6.0 mm = 7.0 mm2 because 6.60 mm2 is more precise than our measurements indicate. 7.5 g 0.8 g

  28. Scientific Notation • Scientific Notation- numbers are written in the form M x 10n, where the factor M is a number greater than or equal to 1 but less than 10 and n is a whole number. • 3,400 m = 3.4 x 103 m .0034 m = 3.4 x 10-3 m • In addition, exponents (n) must be equivalent • In multiplication, exponents (n) are added. • In division, exponents (n) are subtracted.

  29. Guided Practice of Scientific Notation • Addition/Subtraction 5.2 x 106 L 9.3 x 10-4 J • + 3.1 x 106L - 7.1 x 10-4 J • 8.3 x 106 L 2.2 x 10-4 J Multiplication/Division (9.0 x 104 m)(6.0 x 102m) 54 x 106 m2 5.4 x 107m2 36 x 10-3 m /6.0 x 106 s 6 x 10-9 m/s

  30. Proportionality • Direct Proportional- 2 quantities are directly proportional to each other if dividing one by the other gives a constant value • y = k • X • Inverse Proportionality- • 2 quantities if their product is constant • Example: xy = k

More Related