Presentation on theme: "Intro to Physics Science is the study of nature’s rules."— Presentation transcript:
1 Intro to Physics Science is the study of nature’s rules.
2 The Basic Science-Physics Physics is the most basic of all the sciences.Physics is about the nature of basic things, such as:Motion and ForcesEnergyHeatSound and LightMatter and Composition of atoms.
3 Mathematics-The Language of Science When the ideas of science are expressed in mathematical terms, they are unambiguous (clear).Physics equations are systems of relationships.
4 SI UnitsDifferent units of measurement are used for different concepts.Ex: seconds is for timeScientists have agreed upon 7 base units, called SI units for “System Internacional”
6 King Henry Died While Drinking Chocolate Milk Metric PrefixesPrefixes are used to change SI units by powers of 10The main prefixes used in this course are kilo, hecta, deka, deci, centi, and milliKing Henry Died While Drinking Chocolate Milk
7 Check Your Understanding How many meters (m) are in 3 kilometers (km)?3000 meters or 3000 m. Just move the decimal point three to the right.How many grams (g) are in 1,000 centigrams (cg)?10 grams or 10g. Just move the decimal point 2 spaces to the left.
8 The Scientific MethodMaking observations, doing experiments, and creating models or theories to try to explain your results or predict new answers form the essence of a scientific method.Scientific method: an orderly method for gaining, organizing and applying new knowledge
9 Hypothesis: an educated guess Recognize the problemMake a hypothesis about the answerHypothesis: an educated guess3. Predict the consequences of the hypothesis4. Perform experiments to test the predictions5. Formulate the simplest general rule that organizes the three main ingredientsHypothesisPredictionExperimental outcome
10 The Scientific Attitude In science, data and observations are based on facts to eliminate subjectivity.Fact: a close agreement between competent observers who make a series of observations of the same phenomenonLaws and principles are based on repeatable observations that have withstood the test of time and rarely, if ever, change.Law or Principle: A hypothesis that has been tested over and over again and is not contradicted
11 Theories are not fixed, but rather they undergo change. Theory: a synthesis of a large body of information that encompasses well-tested and verified hypothesesTheories undergo change when there is solid experimental evidence to the contrary.** The refinement of theories is a strength of science, not a weakness**
12 Scientific Hypotheses Must be Testable A scientific hypothesis must be TESTABLE.It is more important that there be a means of proving a scientific hypothesis WRONG, rather than there be a means of proving it right.
13 Example 1The alignment of the planets in the sky determines the best time for making decisions.This hypothesis cannot be proven WRONG, nor can it be proven right.This hypothesis is NOT SCIENTIFIC.
14 Example 2Intelligent life exists on other planets somewhere in the universe.Although this hypothesis can be proven correct by finding a single instance of intelligent life elsewhere in the universe, there is no way of proving it WRONG if no life is ever found.This hypothesis is NOT SCIENTIFIC.
15 Check Your Understanding Which of these is a scientific hypothesis?Atoms are the smallest particles of matter.The universe is surrounded by a second universe, the existence of which cannot be detected by scientists.Albert Einstein was the greatest physicist of the twentieth century.The answer is #1 because it is the only statement that can be proven wrong.
16 Accuracy vs. PrecisionWhen a measurement is made, the results often are reported with an uncertainty.Therefore, before fully accepting a new data, other scientists examine the experiment, looking for possible sources of errors, and try to reproduce the results.A new measurement that is within the margin of uncertainty confirms the old measurement.
17 Accuracy: A characteristic of a measured value that describes how well the results line up with the accepted value.How close a measurement is to the real value.Ex: making a basket, nothing but netPrecision: A characteristic of a measured value describing the exactness of a measurement.how replicable a measurement is.Ex: hitting the same place on the backboard every time.
18 Graphing DataA variable is any factor that might affect the behavior of an experimentIndependent and dependentIndependent Variable: the factor that is changed or manipulated during the experimentDependent Variable: the factor that depends on the independent variable
19 Independent variables are always on the x-axis of a graph Dependent variables are always on the y-axis of a graph
21 Check Your Understanding Which variable is the independent variable? How can you tell?Mass is the independent variable because it is on the x-axis and it effects the length of the spring.What is the SI unit for mass? For length?Mass is kilograms and length is meters.
22 Graphing Relationships There are 2 main types of graphing relationships:Directly proportionalHas a positive slopeBoth variables increaseBoth variables decreaseThey do the same thingInversely proportionalHas a negative slopeOne variable increases as the other decreasesThey do opposite things
23 Check Your Understanding Which type of relationship is shown in the graph? How can you tell?It is directly proportional. As the mass increases, so does the length.