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. Physical Science the study of the physical universe. The two main branches are physics and chemistry. These two overlap; the main difference is that physics always deals with the concept of energy. mechanics, - PowerPoint PPT PresentationTRANSCRIPT
The major areas within Physics are:
• mechanics,
• thermodynamics,
• waves,
• optics,
• electricity and magnetism,
• relativity, and
• nuclear physics.
Theories often involve models.
e.g. Atomic Theory
Democritus’ ModelThomson’s ModelRutherford’s ModelBohr’s ModelElectron Cloud Model
Hypotheses & Investigations
Five StepsProblemResearchHypothesis - extends thinking beyond known facts
ExperimentConclusions
Certainty in science
One should always question the validity of scientific Laws, Theories, or Hypotheses.
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
Combinations of these units are used to measure other physical quantities.(e.g. mass density)These are called derived units.
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)
FORCE AND WEIGHTNewton is the accepted unit.Force needed to accelerate a one kilogram mass by one m/s2.
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
Er = (Ea / A) x 100%
where
Er is the relative error, Ea is the absolute error, and A is the accepted value.
Absolute deviation-difference between a single measured value and the average of several measurements made in the same way.
Significant Figures - Those digits in a number that are known with certainty plus the first digit that is uncertain.
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
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
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
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
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
5. All zeros right of a decimal point and following a nonzero figure are significant.
0.07080 ____ sig figs
20.00 _____ sig figs
5. All zeros right of a decimal point and following a nonzero figure are significant.
0.07080 Four sig figs
20.00 _____ sig figs
5. All zeros right of a decimal point and following a nonzero figure are significant.
0.07080 Four sig figs
20.00 Four sig figs
6. Addition and subtraction : rightmost sig fig in a sum or difference is leftmost point of one of the initial measurements.
7. Multiplication and division. Product or quotient cannot have any more sig figs than the least precise factor.
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.
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.
Scalar quantities.quantities expressed by single numbers with appropriate units. Vector quantities.Quantities that require magnitude and direction.Usually depicted by arrows.
A single resultant can be found from these components.Algebraic methods, the parallelogram method, and trigonometric methods can be used to find the resultant.