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 Forces
Energy
Heat
Sound and Light
Matter 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 Units
Different units of measurement are used for different concepts.
Ex: seconds is for time
Scientists have agreed upon 7 base units, called SI units for “System Internacional”

6. King Henry Died While Drinking Chocolate Milk
Metric Prefixes
Prefixes are used to change SI units by powers of 10
The main prefixes used in this course are kilo, hecta, deka, deci, centi, and milli
King 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 Method
Making 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 problem
Make a hypothesis about the answer
Hypothesis: an educated guess
3. Predict the consequences of the hypothesis
4. Perform experiments to test the predictions
5. Formulate the simplest general rule that organizes the three main ingredients
Hypothesis
Prediction
Experimental 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 phenomenon
Laws 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 hypotheses
Theories 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 1
The 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 2
Intelligent 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. Precision
When 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 net
Precision: 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 Data
A variable is any factor that might affect the behavior of an experiment
Independent and dependent
Independent Variable: the factor that is changed or manipulated during the experiment
Dependent 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

20. Check Your Understanding

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 proportional
Has a positive slope
Both variables increase
Both variables decrease
They do the same thing
Inversely proportional
Has a negative slope
One variable increases as the other decreases
They 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.