Presentation on theme: "Scientific Method and Measurement"— Presentation transcript:
1Scientific Method and Measurement Chapter 0Scientific Method and Measurement
2The Method What organized method do scientists use to solve a problem? The scientific methodDefine the problemMake a hypothesisMake observationsRecord dataReview the dataModify hypothesisRetest
3The Method What is the definition of… Hypothesis? Variable? Control? Qualitative Data?Quantitative Data?A prediction or guessWhat changedStays the sameNon-numerical (ex. Blue)Numerical (ex. 55 cm)
4The Method Why is it important not to have too many variables? Hard to tell which, if any, variables affected the resultLimit the variables and have lots of controls
5Theory vs. Law What is the main difference between a theory and a law? A law is a (mathematical) relationship that predicts what happens and is always correct.A theory is an evolving body of information. It has not been proven correct.
6Airplane ChallengeI challenge your team to build a paper airplane that will FLY the farthest distance.Each team will build three planes.3 pieces of paper, 6 paper clips, scissorsYour team will test ONE variable to see which of your three prototypes will work the best.In your observations, you must list at least 3 controls and 1 variable.
7Airplane Challenge Before you fly! What am I testing? What is my first hypothesis?What are 3 controls and my 1 variable?After you fly!What did I observe after the test flights?Please answer these questions in your notebook.
8Precision vs. AccuracyWhat is the difference between precision and accuracy?Accuracy refers to how close it is to the correct valuePrecision refers to how close together a group of measurements are to each other
9Precision vs. AccuracyOn the right hand side of your notes, please draw the following targets with the bullet holes.
10Precision vs. AccuracyLabel the target that is accurate and precise.
11Precision vs. AccuracyLabel the target that is the least precise.
12Precision vs. AccuracyLabel the target that is precise and inaccurate.
13Practice Problem #1An archer shoots three arrows at a target and each land within 1 cm of each other, but none of the arrows are within 30 cm of the center.Explain whether the archer is precise, accurate, neither or both.
14Practice Problem #2The table lists the results of temperature measurements of a beaker of boiling water. The temperature of boiling water is 100 °C.Explain whether each thermometer was accurate, precise, neither or both.
15Precision and Measurement Pick the measuring device that makes the most sense: stick, book or paper clipMeasure the object or area.Estimate the final value. (ex. 0.5, quarter, 1/3)Record your measurements in the table.Object or AreaEstimated MeasurementStick, Book or Paper ClipWidth of the Lab Area (cabinets to cabinets)Length of a Desk (long ways)Height of a Classroom DoorHeight of a Lab BenchThe Depth of a Conceptual Science Book
16Precision and Measurement Which measurement do I feel is the most precise and WHY?What is one benefit AND one drawback to using a smaller unit of measurement?
17Scientific Notation What is scientific notation? A shortcut for writing really large or really small numbersEvery number can be represented by a number between 1 and 10 and multiplied by a power of 10
18Scientific Notation What are some examples of scientific notation? Large numbers190,000,0001.9 x 108Small number5.67 x 10-4
19Scientific Notation How do I do scientific notation? Put a decimal after the first non-zero numberCount the number of spaces the decimal place movedIf the decimal moved to the left, the exponent is positive and if it moved to the right its negativeDrop unwanted zeros
20Scientific Notation What is 35600 in scientific notation? 3.56 x 104Zeros at the end dropped7.21 x 10-4Zeros at the beginning dropped
21Scientific Notation Practice Please convert the following into proper scientific notation:784000100-43211.307.84 x 1051 x 102x 10-2x 1036 x 10-71.30
22Scientific Notation Reversed Please convert the following into standard format:5.68 x 1032.1 x 10-54.309 x 1025680430.9
23Scientific Notation and Calculators What buttons are used on a calculator for scientific notation?Its usually either…EE -or-exp
24Scientific Notation and Calculators What may show up on my screen?On your screen, you may see the following:X10 exponentE exponent(space) exponent
25Scientific Notation and Calculators Put the following number into your calculator and hit equals/enter:4.56 x 1015Please understand that you will need to translate this into proper notation!
26Scientific Notation and Calculators Using your calculator, determine the following answers in scientific notation:Multiply:(4.57 x 10-3)(2.0 x 105)Divide(3.1 x 103)/(4.7x105)9140.0066
27Scientific NotationWhat power are you multiplying and dividing by each time you move a decimal?Powers of 10These powers allow us to comprehend very large (size of galaxies) and very small (size of atoms) numbers
28Dimensional Analysis Why is dimensional analysis important? It allows us to easily convert between units using a series of equivalent fractions
29Dimensional Dominoes - Colors With your team, set up the color dominoes to convert the following colors into new ones.Convert cowpoke brown to deeply redConvert cowpoke brown to pink glitzConvert black leather to orange sizzleConvert orange sizzle to black leatherConvert cowpoke brown to Houdini blue
30Dimensional Dominoes - Units The English unit, the rod, is equal to 16.5 ft. What is this length expressed in meters?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes (right side).Answer = 5.03 meters
31Dimensional Dominoes - Units The portage trails on maps are measured and marked in rods. On a recent canoe trip to the Skagit and Cascade Rivers my brother and I portaged a total of 2342 rods. How many total miles did we carry our gear?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes.Answer = 7.3 miles
32Dimensional Dominoes - Units If a college student smokes an average of 10 cigarettes per day for five years of school, how much money will they have spent on smokes by the time they graduate?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes.Answer = $
33Dimensional Dominoes - Units The weight of bullets and arrows is measured in a unit called the grain. If an arrow weighs 330 grains what is its weight in ounces?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes.Answer = ounces
34Dimensional Dominoes - Units Assuming that you attend school 180 days a year for 8 hours a day from first through twelfth grade, you’d be in class for a total of 2160 school days. How many total years of your life will you have spent in school by the time you graduate?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes.Answer = 1.97 years
35Dimensional Dominoes - Units How many pounds does a 5 gallon pail of water weight?Directions: With your team, set up the unit dominoes to convert the following units into new ones then copy the set-up into your notes.Answer = pounds
36Dimensional Analysis What is a base unit? What is a prefix? Basic unit from which all other units are createdEx. Length – metersEx. Mass – gramsGoes in front of a base unit to indicate how manyEx. Length – kilometersEx. Mass – milligrams
37Dimensional Analysis How many different types are there? Three types: Two step - converting to or from a base unitEx. m to kmThree step - converting from a non-base unit to a non-base unitEx. mm to kmNon-metric – converting between different scales
38Dimensional Analysis - Two Step Please convert 5 kilograms to grams.First fraction is what we have:Second fraction is what we want:Remember… The unit with the prefix gets the one!Multiply across the top and bottom and then divide.
39Dimensional Analysis - Two Step Please convert:2.5 cm to m0.04 J to kJ3.5 g to mg0.5 L to cL3.1 x 104 mL to L50.8 g to ng
40Dimensional Analysis - Three Step Please convert 92 kilograms to milligrams.First fraction is what we have:Second fraction is the conversion to the base unit:Third fraction is what we want:Calculate the same way as before
41Dimensional Analysis - Three Step Please convert:36.0 cm to km52 kg to mg601 mL to cL0.003 dg to cg8 μg to mgkmmg60.1 cL0.03 cg0.008 mg
42Dimensional Analysis – Non-metric What is a non-metric conversion?Use math formulasEx. TemperatureUse other equivalenciesEx. 12 inches = 1 foot
43Dimensional Analysis – Non-metric Please convert:34 inches to feet2 atm to Pa15 °C to °F5 L to gallons2000 calories to J2.8 ftPa59 °F1.32 gallons8368 J