Scientific MethodScientific Method

Steps of the Scientific MethodSteps of the Scientific Method

ObservationObservation HypothesisHypothesis PredictionPrediction TestingTesting Please write down an example of each as Please write down an example of each as

we discusswe discuss Homework page 13 1-5Homework page 13 1-5

Go over homework…..page 13 1-5Go over homework…..page 13 1-5 Parent letters?Parent letters?

HypothesisHypothesis

This is an educated guess based upon This is an educated guess based upon observationobservation

The Gaia HypothesisThe Gaia Hypothesis

TheoryTheory

A theory is an explanation of a set of related A theory is an explanation of a set of related observations or events based upon proven observations or events based upon proven hypotheses and verified many many times by hypotheses and verified many many times by objectiveobjective groups of researchers. One scientist groups of researchers. One scientist cannot create a theory; he can only create a cannot create a theory; he can only create a hypothesis. hypothesis.

A theory is like a car. Components of it can be A theory is like a car. Components of it can be changed or improved upon, without changing the changed or improved upon, without changing the overall truth of the theory as a whole. overall truth of the theory as a whole.

TheoryTheory

An automobile has many moving parts, all An automobile has many moving parts, all designed to move you. An automobile is designed to move you. An automobile is very complex. Sometimes, improvements very complex. Sometimes, improvements are made to one or more component parts. are made to one or more component parts. A new set of spark plugs that are composed A new set of spark plugs that are composed of a better alloy that can withstand heat of a better alloy that can withstand heat better, for example, might replace the better, for example, might replace the existing set. But the car still performs the existing set. But the car still performs the same way.same way.

LAWLAW

Scientific Law---This is a statement of fact –very Scientific Law---This is a statement of fact –very brief-meant to explain an action or set of actions. It brief-meant to explain an action or set of actions. It is generally accepted to be true and universal. It is generally accepted to be true and universal. It is a simple explanation for a natural occurrence.is a simple explanation for a natural occurrence.

A law is more like a slingshot---A slingshot has but A law is more like a slingshot---A slingshot has but one moving part--the rubber band. If you put a one moving part--the rubber band. If you put a rock in it and draw it back, the rock will fly out at a rock in it and draw it back, the rock will fly out at a predictable speed, depending upon the distance predictable speed, depending upon the distance the band is drawn back. the band is drawn back.

Usually summarized with an equationUsually summarized with an equation

GraphingGraphing

Identify the variables Identify the variables

Independent Variable - (controlled by the

experimenter) Goes on the X axis (horizontal) Should be on the left side of a

data table. Dependent Variable -

(changes with the independent variable) Goes on the Y axis (vertical)

Should be on the right side of a data table

Determine the variable range Determine the variable range

Subtract the lowest data value from the Subtract the lowest data value from the highest data value. highest data value.

Do each variable separately. Do each variable separately.

Determine the scale of the graph.Determine the scale of the graph. Determine a scale,Determine a scale,

(the numerical value for each square),(the numerical value for each square),that best fits the range of each variable. that best fits the range of each variable.

Spread the graph to use MOST of the Spread the graph to use MOST of the available space. available space.

Number and label each axis. Number and label each axis.

This tells what data the lines on your graph This tells what data the lines on your graph represent represent

What is wrong with the following graphWhat is wrong with the following graph

Plot the data points Plot the data points

Plot each data value on the graph with a Plot each data value on the graph with a dot. dot.

You can put the data number by the dot, if it You can put the data number by the dot, if it does not clutter your graph does not clutter your graph

Title the graph. Title the graph.

Your title should clearly tell what the graph Your title should clearly tell what the graph is about. is about.

If your graph has more than one set of If your graph has more than one set of data, provide a "key" to identify the data, provide a "key" to identify the different lines. different lines.

Other types of GraphsOther types of Graphs

Bar graph –Bar graph –many typesmany types------things that are countedthings that are counted

Circle graphCircle graph——showsshows how a fixed quantity is how a fixed quantity is broken down into partsbroken down into parts

Histograms and bar graphs look very similarHistograms and bar graphs look very similar—but a histogram is defined as a bar graph —but a histogram is defined as a bar graph that shows frequency data. that shows frequency data.

Parent lettersParent letters Lab reports are due tomorrow by each Lab reports are due tomorrow by each

person and they count as a project gradeperson and they count as a project grade

SI systemSI system

K H D (unit) d c mK H D (unit) d c m I e e meter e e II e e meter e e I L c c liter c n LL c c liter c n L O t a gram i t LO t a gram i t L o I I o I I

1.1. You will decide what unit you are changing You will decide what unit you are changing FROM and what unit you are changing TO.FROM and what unit you are changing TO.

2.2. Starting at the FROM unit, count over Starting at the FROM unit, count over (keeping in mind "left" or "right") to the TO (keeping in mind "left" or "right") to the TO unit.unit.**This will be the number of places you will **This will be the number of places you will move the decimal in your answer. move the decimal in your answer.

EXAMPLES: 32 kilograms = EXAMPLES: 32 kilograms = ______________ grams______________ grams You want to change FROM kilograms TO  You want to change FROM kilograms TO grams. Use diagram and count over, starting grams. Use diagram and count over, starting at kilograms to grams. at kilograms to grams.

K H D  (grams) D C MK H D  (grams) D C M SStarttart 1-> 2-> 3    1-> 2-> 3   

If you are converting from a 'bigger' unit If you are converting from a 'bigger' unit to a 'smaller' unit, move the decimal to a 'smaller' unit, move the decimal

point to the right.point to the right.

If you are converting from a 'smaller' unit to a If you are converting from a 'smaller' unit to a 'bigger' unit, move the decimal point to the 'bigger' unit, move the decimal point to the

left.left.

'dec-' means 10 -- as in decimal, decade;  so a 'dec-' means 10 -- as in decimal, decade;  so a decimeter is one-tenth of a meter.  Move one decimeter is one-tenth of a meter.  Move one decimal place. decimal place.

'cent-' means 100 -- as in percent, century;  so a 'cent-' means 100 -- as in percent, century;  so a centimeter is one-one hundredth of a meter.  Move centimeter is one-one hundredth of a meter.  Move two decimal places. two decimal places.

'milli-' means 1,000 -- as in millipede. Oh, well.  A 'milli-' means 1,000 -- as in millipede. Oh, well.  A millimeter is one-one thousandth of a meter.  millimeter is one-one thousandth of a meter.  Move three decimal places. Move three decimal places.

1 meter is how many millimeters? 1 meter is how many millimeters?  [1 m = ___________ mm]  Meter is bigger [1 m = ___________ mm]  Meter is bigger

than millimeter, so you move the decimal than millimeter, so you move the decimal point to the right.  Millimeter differs from point to the right.  Millimeter differs from meters by three decimal places.  Move the meters by three decimal places.  Move the decimal three places to the right. decimal three places to the right. 1 m = 1000 mm. 1 m = 1000 mm.

3.2 m is how many centimeters?  3.2 m is how many centimeters?  [3.2 m = _________ cm]  Meter is bigger [3.2 m = _________ cm]  Meter is bigger

than centimeter, so you move the decimal than centimeter, so you move the decimal point to the right.  Centimeter differs from point to the right.  Centimeter differs from meter by two decimal places.  Move the meter by two decimal places.  Move the decimal two places to the right. decimal two places to the right. 3.2 m = 320 cm. 3.2 m = 320 cm.

Complete these examplesComplete these examples

0.5 m is how many mm? 0.5 m is how many mm? 0.045 m is how many cm? 0.045 m is how many cm? 4.5 cm is how many mm? 4.5 cm is how many mm? 45 mm are how many m? 45 mm are how many m?

1--Meters to millimeters is three places to the right. .5 m = 1--Meters to millimeters is three places to the right. .5 m = 500 mm. 500 mm.

2--M to cm is two places to the right. 2--M to cm is two places to the right. 0.045 m = 4.5 cm. 0.045 m = 4.5 cm.

3--Cm is bigger than mm.  Cm and mm differ by one decimal 3--Cm is bigger than mm.  Cm and mm differ by one decimal point. Move the decimal point once to the right. 4.5 cm = point. Move the decimal point once to the right. 4.5 cm = 45 mm. 45 mm.

4--Mm is smaller than m, so the decimal point moves to the 4--Mm is smaller than m, so the decimal point moves to the left.  Mm differ from m by three decimal places.  Move the left.  Mm differ from m by three decimal places.  Move the decimal point to the left three places. decimal point to the left three places. 45 mm = 0.045 m. 45 mm = 0.045 m.

StandardsStandards There must always be an exact quantity that people use to There must always be an exact quantity that people use to

agree to use for comparisonagree to use for comparison Just like every experiment must have a controlJust like every experiment must have a control metermeter (m)distance"The metre is the length of the path travelled (m)distance"The metre is the length of the path travelled

by light in vacuum during a time interval of 1/299 792 458 of a by light in vacuum during a time interval of 1/299 792 458 of a second.“second.“

secondsecond (s)time"The second is the duration of 9 192 631 770 (s)time"The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 the two hyperfine levels of the ground state of the caesium 133 atom.“atom.“

ampereampere (A)electric current"The ampere is that constant current (A)electric current"The ampere is that constant current which, if maintained in two straight parallel conductors of which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these metre apart in vacuum, would produce between these conductors a force equal to 2 × 10-7conductors a force equal to 2 × 10-7

Base unitsBase units

The most frequently used base unitsThe most frequently used base units See page 15See page 15 Prefixes and base unitsPrefixes and base units You must memorize thisYou must memorize this

Complete concept mapComplete concept map Take up labTake up lab Book covers due TUESDAYBook covers due TUESDAY Test is Friday changed Test is Friday changed Complete mini lab for homework/test reviewComplete mini lab for homework/test review Complete skills activity page 16 or Complete skills activity page 16 or

worksheet worksheet

Page 16 answerPage 16 answer 1cm=10mm1cm=10mm 11cm X 11cm X 10mm10mm

1cm1cm Cm cancel out and complete the mathCm cancel out and complete the math 11 x 10mm=110mm11 x 10mm=110mm

VolumeVolume

Liquid volume—there is no side to measure Liquid volume—there is no side to measure so………….you want to know how much will so………….you want to know how much will a container holda container hold

Most common units are liter and milliliterMost common units are liter and milliliter

Formula = l x w x hFormula = l x w x h

Units are always cubed cm3 dm3 L3Units are always cubed cm3 dm3 L3

1ml=1cm31ml=1cm3

DensityDensity

Density = Mass/VolumeDensity = Mass/Volume how could you distinguish a metric ton of how could you distinguish a metric ton of

feathers versus a metric ton of bricks if you feathers versus a metric ton of bricks if you could not see them? could not see them?

One metric ton of either feathers or bricks One metric ton of either feathers or bricks will have same mass of1,000 kilograms (one will have same mass of1,000 kilograms (one metric ton). metric ton).

a metric ton of feathers will occupy a a metric ton of feathers will occupy a volume of almost 400 million cm3(about the volume of almost 400 million cm3(about the size of four tractor trailer trucks),size of four tractor trailer trucks),

a metric ton of bricks will occupy only one-a metric ton of bricks will occupy only one-half million cm3 (about the size of a large-half million cm3 (about the size of a large-screen TV). screen TV).

The bricks are denser than the feathers The bricks are denser than the feathers because their mass is packed into a smaller because their mass is packed into a smaller volume. This relationship between the mass volume. This relationship between the mass and volume of a substance is what defines and volume of a substance is what defines the physical property of density the physical property of density

Derived unitsDerived units

Don’t ever forget to put the unit when you Don’t ever forget to put the unit when you are discussing any measurementare discussing any measurement

combinations of the base units. combinations of the base units.