Transcript The Toolbox of Science

The Toolbox of Science
But First……...
• What is Science?
Science
• Science is a method of learning about our
natural world.
• Science is also the collected knowledge that
has been gained by studying our natural
world.
Science Skills
• Making an Observation
Science Skills
• Making an Observation
• Classifying Data
Science Skills
• Making an Observation
• Classifying Data
– Data is information you collect as you observe
something.
Science Skills
• Making an Observation
• Classifying Data
Science Skills
• Making an Observation
• Classifying Data
• Modeling and Simulation
Science Skills
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Making an Observation
Classifying Data
Modeling and Simulation
Measuring
Science Skills
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Making an Observation
Classifying Data
Modeling and Simulation
Measuring
Analyzing Data
Science Skills
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Making an Observation
Classifying Data
Modeling and Simulation
Measuring
Analyzing Data
Making a Prediction
The Scientific Method
• Make careful observations of nature.
• Form a hypothesis to explain a specific
phenomenon or event.
– a possible explanation.
The Scientific Method
• Perform experiments to replicate and
understand the phenomenon.
– Variable
• Factors that can be changed in an experiment.
– Manipulated Variable
• Variable that is changed to test a hypothesis.
– Responding Variable
• Variable that is changed as a result of the experiment
The Scientific Method
• Gather evidence through experimentation to
support, reject, or modify their hypothesis.
The Scientific Method
• Repeat these steps until the weight of
evidence indicates a sound hypothesis.
The Scientific Method
• Create a theory based on a sound hypothesis
that has not been proven false by
experimentation.
The Scientific Method
• Accept a theory as a law, if it is proven to
be a non-varying phenomenon.
The SI system
• Known as the International System of Units
– So……..why not IS?
• Well, it turns out it REALLY is the abbreviation for
Systéme International d’Unités
– Those silly French people.
The SI system
• So much easier since it is based on base 10.
– Wrenches
The SI system
• Common Prefixes
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Mega
kilo
hecto
deka
deci
centi
milli
micro
M
k
h
da
d
c
m
m
1000000
1000
100
10
0.1(one tenth)
0.01(one hundredth)
0.001(one thousandth)
0.000001(one millionth)
The SI system
• Standard unit of measure for length is the
meter (m)
– 1 meter = 3.280 839 895 feet
– The distance for the Earth to the Moon is
384,403 km or…..384,403,000m
– The average male American men’s height is
177 cm, which is about 5 foot - 10 inches tall.
– Women’s average height is 163 to164 cm
The SI system
• Standard unit of measure for mass is the
gram (g).
– 1 gram = 0.035 273 962 ounce
– The average 40-49 year old male has a mass of
about 82.6kg or 182 pounds. Women - 67.7kg
– 1 Sweet and Salty granola bar by Nature Valley
has a mass of 35g or 1.2 ounces.
• And 170 calories
– and 9g of fat
The SI system
• Standard unit of measure for volume is the
liter (L).
– 1 liter = 33.814 022 702 ounce [US, liquid]
– One 12 ounce can of pop = 0.354 882 355 liter
• or 354.882 354 75 milliliter.
The SI system
• Standard unit of measure for temperature is
the degree Celsius (C).
– 1 degree Celsius = 33.8 degree Fahrenheit
– 2 degree Celsius = 35.6 degree Fahrenheit
– 3 degree Celsius = 37.4 degree Fahrenheit
– But wait…...
The SI system
• Converting F to Celsius
– Co = 5/9(Fo - 32)
• Converting C to F
• Fo = (9/5 Co) + 32
• Average human body temperature is 37°C
• or 98.6 F
Some Basic Skills
• Significant Digits
– All non-zero digits in a number are significant.
• 236.345
6 significant digits
• 23
2 significant digits
Significant Digits
– Zeros between other digits in a number are
significant.
• 40006
• 1.004
5 significant digits
4 significant digits
Significant Digits
– Zeros at the end of a decimal number are
significant.
• 40.100
• 1.00000
5 significant digits
6 significant digits
Significant Digits
– Zeros at the beginning of a number are NOT
significant.
• 0.000001
• 026
1 significant digits
2 significant digits
Significant Digits
• What about these??
– 13300
– 220
– 10
– Who knows?
Significant Digits
• In any calculation, the number of
significant digits in the answer can only
be as large as the smallest number of
significant digits in any one of the
numbers in the calculation.
Examples:
• 0.3467 + 0.123754 + 0.64 = 1.110454
– Not so fast!
– Using the significant digits rule: since 0.64 has
only two significant digits, then the answer can
have only two significant digits. The correct
solution would be 1.1
Significant Digits
• A common sense exception…
– Let’s say I have 8 weights each with a mass of
5.000 grams. Simple math would suggest that
you should just multiply 8 times 5.000 like so.
5.000 x 8 = 40……..But how many significant
digits??
– In this case, the 8 is a finite number with
infinite significant digits. So the significant
digits in 8 are ignored. It will be 40.00.
Scientific Notation
• To write a number in scientific notation:
• Put the decimal after the first digit and drop
the zeroes.
– Let’s convert 2,340,000
– So……….2,340,000 becomes
• 2.34
Scientific Notation
– Now count the spaces it took to get to the new
decimal point.
• 6 spaces
Scientific Notation
– So, put it all together 2,340,000 becomes…
• 2.34 x 10 6
Scientific Notation
• To go the other way……
– Let’s convert 0.0000000034
– So………. 0.0000000034
– 3.4
Scientific Notation
– Now count the spaces it took to get to the new
decimal point.
• 9 spaces
Scientific Notation
– So, put it all together 0.0000000034 becomes…
• 3.4 x 10 -9
Scientific Notation
• HOW TO CALCULATE:
• multiplication: multiply coefficients, add
exponents.
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(2.0 x 103) x (4.0 x 104) = 8.0 x 107
Scientific Notation
• HOW TO CALCULATE:
• division: divide coefficients, subtract
exponents.
• (7.5 x 106) x (2.5 x 102) = 3.0 x 104
Scientific Notation
• HOW TO CALCULATE:
• addition: adjust powers of ten so two
numbers are the same, then add.
• (6.2 x 102) + (3.3 x 103)
• (.62 x 103) + (3.3 x 103)= 3.92 x 103
Scientific Notation
• HOW TO CALCULATE:
• subtraction: adjust powers often so two
numbers are the same, then subtract.
• (8.7 x 105) - (2.1 x 104)
• (8.7 x 105) - (.21 x 105) = 8.49 x 105
Accuracy and Precision
• Accuracy
– The quality of being near to the true value.
Accuracy and Precision
• Precision
– The quality of being reproducible in amount or
performance.