Sponge: List five scientists you saw in the Mechanical Universe film.

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Sponge List five scientists you saw in the
Mechanical Universe film.
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Physical Science the study of the physical
universe.
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The two main branches are physics and chemistry.
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These two overlap the main difference is that
physics always deals with the concept of energy.
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The major areas within Physics are

• electricity and magnetism,
• relativity, and
• nuclear physics.

• mechanics,
• thermodynamics,
• waves,
• optics,

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Scientific MethodLAWS-describe the relationships
between various phenomena
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• Boyles Law
• Charles Law
• Coles Law

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Scientific Law-expressed by wordsLaws in
physics-expressed by math equations
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THEORY-reasonable explanation of observed events
that are related.
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Theories often involve models.e.g. Atomic
Theory Democritus Model Thomsons
Model Rutherfords Model Bohrs
Model Electron Cloud Model
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Experiments test theories.
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Hypotheses InvestigationsFive
Steps Problem Research Hypothesis - extends
thinking beyond known facts Experiment Conclusio
ns
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Certainty in scienceOne should always question
the validity of scientific Laws, Theories, or
Hypotheses.
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METRIC SYSTEM - uses a decimal basis for
multiples and fractions of the basic units of
measure.
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International System of UnitsThe SI
system(Systeme International dUnites)
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Units of measure are used to describe physical
quantities.e.g. the meter is the unit of length
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Seven fundamental units of measure

• 1. length meter
• 2. mass kilogram
• 3. time second
• 4. electric current ampere
• 5. temperature kelvin
• 6. amount of substance mole
• 7. luminous intensity candela

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Combinations of these units are used to measure
other physical quantities.(e.g. mass
density)These are called derived units.
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Modern metric system often called the MKS
system.(meter, kilogram, second)
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METERStandard meter was a metal bar until
1960.Now 1 meter the distance light travels
in a vacuum in 1/299 729 458th of a second.
(speed of light is no longer subject to revision)
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KILOGRAMMass of the standard kilogram. Only
measure that still is a natural object.
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FORCE AND WEIGHTNewton is the accepted
unit.Force needed to accelerate a one kilogram
mass by one m/s2.
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THE SECONDone second 9 192 631 770 vibrations
of cesium-133 atoms.
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1 ml H2O 1 cm3 H2O 1 g H2O heat required
to change temp of 1 g liquid H2O 1 centigrade
(Kelvin) is 1 calorie
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The metric measures are related around liquid
water.
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It is important to indicate the degree of
uncertainty in measurements so far as it is
known.
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ACCURACY - the closeness of a measurement to the
accepted value for a specific physical quantity.
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absolute error- actual difference between the
accepted value and the measured value.
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Ea O - A,whereEa is the absolute error,
O is the observed value, and A is the accepted
value.
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Relative Error - expressed as a percentage.
(often called percentage error)
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Er (Ea / A) x 100whereEr is the relative
error, Ea is the absolute error, and A is the
accepted value.
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PRECISION - the agreement among several
measurements that have been made in the same way.
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Precision is expressed in terms of DEVIATION.
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Absolute deviation-difference between a single
measured value and the average of several
measurements made in the same way.
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Relative Deviation-the percentage average
deviation of a set of measurements.
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Significant Figures - Those digits in a number
that are known with certainty plus the first
digit that is uncertain.
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RULES1. all nonzero figures are significant
112.6 ____ sig figs
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RULES1. all nonzero figures are significant
112.6 Four sig figs
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2. All zeros between nonzero figures are
significant108.005____sig figs
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2. All zeros between nonzero figures are
significant108.005 Six sig figs
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3. Zeros right of a nonzero figure, but left of
understood decimal point, are not significant
unless indicated.109 000 _____ sig figs
_109 000 _____ sig figs
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3. Zeros right of a nonzero figure, but left of
understood decimal point, are not significant
unless indicated.109 000 Three sig figs
_109 000 _____ sig figs
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3. Zeros right of a nonzero figure, but left of
understood decimal point, are not significant
unless indicated.109 000 _____ sig figs
_109 000 Five sig figs
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4. Zeros to the right of a decimal point but to
the left of a nonzero figure are not
significant. Zero to the left of decimal point
is never significant.0.000 647 _____sig figs
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4. Zeros to the right of a decimal point but to
the left of a nonzero figure are not
significant. Zero to the left of decimal point
is never significant.0.000 647 Three sig figs
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5. All zeros right of a decimal point and
following a nonzero figure are significant.0.070
80 ____ sig figs20.00 _____ sig figs
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5. All zeros right of a decimal point and
following a nonzero figure are significant.0.070
80 Four sig figs20.00 _____ sig figs
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5. All zeros right of a decimal point and
following a nonzero figure are significant.0.070
80 Four sig figs20.00 Four sig figs
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6. Addition and subtraction rightmost sig
fig in a sum or difference is leftmost point of
one of the initial measurements.
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13.05 309.2 3.785 326.035
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13.05 309.2 3.785 326.035
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13.05 309.2 3.785 326.0
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7. Multiplication and division. Product or
quotient cannot have any more sig figs than the
least precise factor.
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3.54 4.8 0.5421 9.211 363 2
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3.54 4.8 0.5421 9.211 363 2
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3.54 4.8 0.5421 9.211 363 2
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3.54 4.8 0.5421 9.2
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RoundingIf the figure to be dropped is 4 or
less, the preceding figure is not changed.If the
figure to be dropped is 5 or more, the preceding
figure is raised by 1.
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SCIENTIFIC NOTATIONM 10nM is a number
greater than or equal to 1, but less than 10. n
is the number of places the decimal point has
been shifted.Moved left, n is pos.Moved right,
n is neg.
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Order of magnitude. numerical approximation to
the nearest power of ten.
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DATA, EQUATIONS, GRAPHS,DIMENSIONAL ANALYSIS.
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Scalar quantities.quantities expressed by single
numbers with appropriate units. Vector
quantities.Quantities that require magnitude and
direction.Usually depicted by arrows.
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Two vectors that act on the same point are called
components.
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A single resultant can be found from these
components.Algebraic methods, the parallelogram
method, and trigonometric methods can be used to
find the resultant.
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RULES OF PROBLEM SOLVING
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1. Carefully find what is being asked. Write
down all given data.
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2. Write down all the symbols and units for the
quantities called for.
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3. Write down the basic equation relating the
known and unknown quantities.
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4. Solve for the unknown quantity to find the
working equation.
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5. Substitute the given data into the working
equation.
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6. Perform the mathematical operations with the
units alone.Unit analysisDimensional analysis
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7. Perform the mathsig figs!!!!
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8. Check the answer for reasonableness
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8. Check the answer for reasonableness
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8. Check the answer for reasonableness
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9. Review the entire solution.
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