2. Physics

3. *The Scientific Method* The way we do science Based on Rational thinking 1.Make an observation Scientific attitude We MUST accept the findings, even if they’re not what we want to find 2. State a question 3.Form a hypothesis (Use background knowledge to answer your question) 4. Test hypothesis / Do Experiments 5. Interpret data from experiments and draw conclusions 6. Revise hypothesis (go back to step 3) if necessary

4. Engineers 1.Asking questions and defining problems 2.Developing and using models 3.Planning and carrying out investigations 4.Analyzing and interpreting data 5.Mathematics and computational thinking 6.Constructing explanations and solutions 7.Engaging in argument from evidence 8.Obtaining, evaluating, & communicating information The branch of science that deals with the technology for the production and the manufacture of products to enhance our lives. Engineers

5. Engineering Method

6. Scientific vs Engineering Methodology © 2014 John Wiley & Sons, Inc. All rights reserved.

7. Bar Graphs: Bar graphs are one of the many techniques used to present data in a visual form so that the reader may readily recognize patterns or trends.

8. Pie Graph: If we are more interested in the percent relationships within your data, a pie graph might give you a better visual choice.

9. The Axis A. The independent variable is normally plotted on the x-axis. B. The dependent variable is plotted on the Y-axis. C. Label both axis with quantity expressed and the units of the quantity.. Title A. Main Title should tell what the graph describes. B. Subtitle: (quantity on the Y-axis) vs (quantity on the X-axis) C. Example: D ensity Mass(g) vs Volume (mL) Scaling A. Scale each axis so that at least three-fourths of the page (graph) is used in each direction. B. Scale division will make easy plotting and interpretation of data if arranged in multiples of 0.5, 1, 2, 4, 5 and 10. C. If only the first quadrant is needed for the data, place the origin in the lower left hand corner of the page. Drawing the curve. A. For most experimental data, do not “connect the dots”. Draw a smooth curve through the lines whether it be curved or straight.

10. X - Axis Y - Axis DENSITY Mass (g) vs. Volume (mL) Mass (g) Volume (mL) Let’s see a Linear graph! 10 20 30 10 30 20

11. X - Axis Y - Axis Acceleration Velocity (m/s) vs. Time (s) Velocity (m/s) Time (s) Let’s see a hyperbolic graph! 10 20 30 50 150 100

12. Math in Science Measurements and calculations are essential parts of the science we practice today

13. Scientific Notation To save space from writing long numbers, scientists often shorten them using scientific notation. 16,000,000,000 = 1.6 x 10 10 0.000000025 = 2.5 x 10 -8 6.022 x 10 23 = 602,200,000,000,000,000,000,000 Scientific notation always has a number followed by x 10 x

14. Scientific Notation Expanded form to Scientific Notation 2,500,000,000,000 = ????? In scientific notation, we always want the decimal after one non zero So we move the decimal after the 2 We then count how many spots we would need to move the decimal to make the number we have – this goes as the exponent. 2,500,000,000,000 = 2.5 x 10 12 From 2.5 we would have to move the decimal to the right 12 spaces In scientific notation we show all significant digits (more to come!)

15. Scientific Notation Scientific Notation to Expanded Form 9.34 x 10 7 = ???? The exponent is positive 7. It tells us to move the decimal 7 spots to the right. If it were negative it would tell us to move it to the left 9.34 x 10 7 = 93,400,000. Notice the decimal move 7 spots right

16. Scientific Notation Try these…  2.5 x 10 6 = ______________________  3.9 x 10 -7 = ______________________  8,320,000,000 = ______________________  0.000048 = ______________________ 2,500,000 0.00000039 8.32 x 10 9 4.8 x 10 -5

17. Significant Digits FYI..All numbers written before the x 10 x are considered significant in number written in scientific notation Digits other than zeros are always significant 212 = _____ significant digits 0.9987 = _____ sig. figs. Zeros after the decimal that end the number are always significant 91.26 = _____ sig. figs. 91.2600 = ___ sig. figs. 3 4 4 6_6_

18. Significant Digits Zeros between other significant digits are always significant 18.006 = _____ sig. figs. 2005 = _____ sig. figs. Zeros used for spacing are not significant 12000 = _____ sig. figs. 0.000123 = _____ sig. figs. 5 4 2 3

19. Significant Digits Tell the number of sig. figs. 2.030 = _____12.0 = _____ 1000 = _____0.00020 = _____ 2001.02 = _____60 = _____ 0.009m = _____1,000,001 = _____ 1000.0 = _____145236 = _____ 43 1 2 6 1 1 7 5 6

20. The Metric System Scientists around the world share there experimental findings. In order to do this, they share a single set of units. SI Units: “International System of Units” A measuring system to be used by all scientists Streamlines the sharing of materials between scientists. Promotes a better understanding of information passed between scientists of different regions. SI = systeme international

21. The Metric System cont. The SI system is also known as the Metric System – Uses the decimal system – units of ten – Uses prefixes to denote size Multiplication Factor PrefixSymbol 1,000,000,000 = 10 9 giga-G 1,000,000 = 10 6 mega-M (capital) 1,000 = 10 3 kilo-k 100 = 1 2 hecto-h 10 = 10 1 deca-da 1 = 10 0 0.1 = 10 -1 deci-d 0.01 = 10 -2 centi-c 0.001 = 10 -3 milli-m (lower case) 0.000001 = 10 -6 micro-  0.000000001 = 10 -9 nano-n  Base units such as  “g”gram, “m”meter, “L” Liter

22. Metric Prefixes The prefixes are used in front of the unit – 1 kilogram = 1kg = 1 thousand grams – 1 megameter = 1Mm = 1 million meters – 1 centimeter = 1cm = 0.01 meters (1/100) – 1 microsecond = 1  s = 0.000001 seconds (1/1,000,000) – 1 millimeter = 1mm = 0.001meters (1/1000)

23. Units Continued… Unit for distance mass time volume U.S. foot Pound Second gallon Metric meter kilogram Second liter

24. Conversions Conversions are used to change one set of units to a different more useful unit. 1,000,000 mm = 1 km 50 cm = 0.5 m They also can be used to change units in the US system to Metric 1 foot = 0.305 meters 10 pounds = 4.536 kilograms

25. So, how do we do conversions? Start with the following T-chart GivenConversion Factor 1_ (same units as the given) Our starting measurement (Given) goes in the upper left The conversion factor goes to the upper right And in the lower right, put 1 and the given unit

26. Conversions Cont. Lets try it! Lets convert 150 centimeters to meters The given is 150 cm. 150 cm

27. Conversions Cont. The lower right section simply gets 1 of the given units – This is done so the units will cancel out 150 cm 1 cm

28. Conversions Cont. We’re converting 150 centimeters to meters To find the conversion factor we look at the exponents of the multiplication factors of the given and the new unit. Go find the exponents for cm and m. For or our problem cm = 10 -2 m = 10 0 Now subtract the meter’s (new) exponent from the centimeter’s (given). -2 – 0 = -2 This is our conversion factor exponent. 150 cm 10 -2 m Notice: we use the new units 1 cm

29. Conversions Cont. The T-chart represents a math function 150 cm 10 -2 m 1 cm  divide multiply x Horizontal lines represent division (  ) Vertical lines represent multiplication (x)

30. Conversions Cont. The conversion factor 10 -2 tells us to move the decimal 2 spots to the left. (if positive, move right) 150 cm 10 -2 m 1 cm = 1.5 m Conversion factor The cm in the top will cancel out the cm on the bottom So the final answer is 1.5 m (The zero drops out since it is not a significant digit)