2. An Introduction to Physics

3. The Scientific Method l Make an observation l Formulate a hypothesis l Test the hypothesis via experiments l Evaluate the hypothesis l Reevaluate/Conclusions

4. Scientific Measurement: The Metric System

5. What do we use this for? l The Metric System is the key to unlock the world, for how can we know what we have if we don’t know how much we have

6. Parlez-vous francais? l The Metric System is often called the International System of Units

7. What are the basic SI units?

8. Where can I find the Metric Prefixes?

9. Metric Conversions l How do we convert from one unit to another? –Since bases are multiples of 10 all we have to do is “jump” to the correct prefix l BiggersBase unitSmallers l M, k, h, dam, l, g, sd, c, m, μ

10. Convert these: l 5 km to dam5km to mm l 5 dm to cm5 hm to cm l 5 mm to km5 dm to dam

12. Significant Digits l Numbers (digits) that show the degree of accuracy and precision of a measurement l Accuracy: How close a measurement is to the accepted value l Precision: Repeatability of a set of measurements to be similar in value

15. Atlantic-Pacific Rule l Atlantic: –If the decimal is absent, start counting from the right (Atlantic Ocean) side with the first nonzero. Once you start counting keep on counting. –2040

16. Atlantic-Pacific Rule l Pacific –If the decimal is present, start counting from the left (Pacific Ocean) side with the first nonzero. Once you start counting keep on counting. –0.034500

17. How many significant digits are in these numbers? l 2,339,009 l 0.00987 l 0.005600 l 203040

18. Math with Significant Digits l When you add and subtract simply line up the decimals and keep the fewest places after the decimal in your answer. l 234.0098 + 3.01 = ? l 234.0098 – 30.0 = ?

19. Math with Significant Digits l When you multiply and divide, your answer should have the fewest digits shown in the original numbers. l 2.2 x 3 = ? l 2.100 / 7.0 = ?

20. Parallax l Error in measurement due to the position of the viewer’s eye in comparison to the position of the object to be measured

21. Parallax Activity l You will measure the diameter of a paper circle using three different methods. 1.Circle on top of ruler while looking directly overhead 2.Ruler on top of circle while looking directly overhead 3.Ruler on top of circle while looking from the side l You will need to repeat each, 3 times!

22. Data TrialMethod 1Method 2Method 3 1 2 3