1. The right tools for the job A carpenter shows up with a hammer, a measuring tape and a pencil every day to do work. A doctor has his scalpel to make the cut in surgery A physics student has number systems that allow communication across the world that is standard… Yep, It’s alphabet soup!`

2. 2.1 Measurement 1. Scientific Notation = a way of expressing very small or very large numbers using powers of 10 6,700,000,000 = 6.7 x 10 9 0.00000000056 = 5.6 x 10 -10 Coefficient = number between 1 and 10 Superscript = exponent Positive exponents indicate large numbers, moving decimal to the right Negative exponents indicate small numbers, moving decimal to the left

3. When you multiply, add the exponents When you divide, subtract the exponents Second part of Sci Not sheet If your answer isn’t in scientific notation, convert it (5.1 x 10 6 m) x (3.1 x 10 2 m) = 15.81 x 10 8 m 2 Remember to multiply or divide units also!! = 1.581 x 10 9 m 2 (4.5 x 10 5 m) x (2.0 x 10 3 m) = 9.0 x 10 8 m 2 (6.4 x 10 6 m) / (2.0 x 10 9 s) = 3.2 x 10 -3 m/s

4. 1. Scientific Notation = a way of expressing very small or very large numbers using powers of 10 Coefficient = number between 1 and 10 Superscript = exponent Positive exponents indicate large numbers, moving decimal to the right Negative exponents indicate small numbers, moving decimal to the left

5. What is 25390 in scientific notation? 1.2.5390 x 10 4 2.2.5390 x 10 -4 3.25.390 x 10 3 4.25.390 x 10 -3 Answer is 1.

6. What is 0.00345 in scientific notation? 1.3.45 x 10 3 2.3.45 x 10 -3 3.3.45 x 10 -2 4.34.5 x 10 4 Answer 2.

7. What is 5.6 x 10 5 in normal notation? 1.56,000 2.560,000 3.0.000056 4.0.00056 Answer 2

8. What is 1.23 x 10 -2 in normal notation? 1.123 2.1230 3.0.0123 4.0.00123 Answer 3.

9. 2. SI Units of Measurement A. Fundamental or Base units You must memorize these. See page 711 Merrill

10. B. Derived Units = combinations of base units mL = cm 3 L = dm 3 QuantitySymbol Aream2m2 Volumem3m3 Velocitym/s Accelerationm/s 2 DensityKg/m 3

11. C. Metric Prefixes Indicate operations on the base unit Ex. Centimeter means multiply meter by 0.01 or by 10 -2 Phys B, you must memorize Giga through nano. See page 711 Merrill. What patterns do you see that will assist you? Brainstorm it now…

12. How many meters is one centimeter? 1.1000 2.100 3.1/100 4.1/10 Answer 3.

13. How many meters is one millimeter? 1.1/1000 2.1,000,000 3.1/1,000,000 4.1000 Answer 1.

14. Conversion factor 2 m x100 cm 1 m = 200 cm 3 cm x1 m 100 cm = 0.03 m Select a conversion factor that will cancel units 2 m x 1 m 100 cm = 2 m*m/cm – this doesn’t make sense ratio/fraction of equivalent amounts (ex. 100 cm/1 m or 1m/100 cm)

15. Which conversion factor would you use to convert km to m? 1.1 km/1000 m 2.1000 km/1 m 3.1000 m/1 km 4.1 m/1000 km ans 3.

16. Which conversion factor would you use to convert m to km? 1.1000 m/1 km 2.1000 km/1 m 3.1 m/1000 km 4.1 km/1000 m ans 4

17. Which conversion factor would you use to convert m to cm? 1.100 cm/1 m 2.100 m/1 cm 3.1 m/100 cm 4.1 cm/100 m ans 1.

18. Which conversion factor would you use to convert cm to m? 1.100 cm/1 m 2.1 m/100 cm 3.100 m/1 cm 4.1 cm/100 m ans 2

19. D. Converting units Use a conversion factor = ratio of measurements equal to 1 Fill in the conversions below if you can 2 m x100 cm 1 m = 200 cm 3 cm x1 m 100 cm = 0.03 m Select a conversion factor that will cancel units

20. Off the chart… 2000 mockingbirds = ? 2 kilomockingbirds 10 millipedes =? 1 centipede OMG Can you think of one of your own?

21. 2.2 Making Measurements Always include units Write all the numbers that you know, plus one that you guess 15.9 cm 15.0 cm

22. What is the length of the following? 1.11 cm 2.11.65 cm 3.11.6 cm 4.12.6 cm

23. What is the length of the following? 1.14 2.14.0 3.14.5 4.13.99 Sci & Conv Review Finish SI Lab

24. Practice makes perfect With the guidance of the teacher you will now use an overhead ruler, take measurements indicated and express them using the proper number of significant digits Shake a leg, Cadiz! It’s either in your mechanics notebook or lab folder …

25. Measuring skills with correct number of sig figs

26. Read these for practice 1.54 cm 5.42 cm AND the answers are…

27. Avoid Parallax Error

28. Read these for practice Note that the stop watch is in minutes and seconds. 9’41.5” Answer is…

29. Read these for practice Answer is… 18.45 ml Read the bottom of the meniscus

30. Read these for practice Bonus work: How to read a micrometer

31. Read these for practice Bonus work: How to read a micrometer caliper

32. 1. Limits of Measurement A. Precision = how exact a measurement is, number of significant figures Ex. 5.15 is more precise than 5

33. All non-zero digits are significant Zeroes are significant except: Ex. 100, 200, 350, 61700 So how many sig figs are here??? when following a digit in which no subsequent non zero digit appears when preceding a digit after a decimal point in which no preceding digit appears Ex. 0.0004, 0.03 So how many sig figs are here??? B. B.Significant figures = number of digits known in a measurement including the last estimated digit Demonstration: How the number of significant figures is determined using a ruler. 236001 6 2361.0007

34. How many sig figs are in 15? 1.5 2.4 3.2 4.1 3 The answer is number…

35. How many sig figs are in 15.0? 1.4 2.3 3.2 4.1 answer 2

36. How many sig figs are in 15.06? 1.4 2.3 3.2 4.1 answer 1.

37. How many sig figs are in 0.0056? 1.1 2.2 3.3 4.4 5.5 answer 2

38. How many sig figs are in 4.506? 1.1 2.2 3.3 4.4 answer 4

39. C. Calculations with significant figures When multiplying or dividing: keep the number of significant digits that are in the least significant number (ex. 5.61 x 2.0 = 11; 2.34 x 3.2 = 7.5) 2.34 x 3.2 7.488 ----> 7.5

42. Adding and subtracting numbers of differing precision requires that we TRUNCATE the final answer. Ex. Find the perimeter of the figures and you will see why truncating the final answer is logical. DO THIS NOW AS A CLASS EXERCISE. A good way to think of this is your final answer must be as rough as the roughest measurement

43. What is 35.78 / 4.4 ? 1.8.1318181818 2.8.131 3.8.13 4.8.1 ans 4.

44. What is 105 / 3.4 ? 1.30.88235294 2.30.88 3.30.9 4.31 ans 4

45. What is 6.798 x 9.25 ? 1.62.8815 2.62.88 3.62.8 4.63 ans 3

46. When adding or subtracting: keep the number of decimal places that are in the number with the least (ex. 1.536 + 2.0 = 3.5; 2.4456 + 4.5 = 6.9) 2.4456 +4.5 6.9456 ----> 6.9

47. What is 4.5 + 8.99 ? 1.13.49 2.13.5 3.13 ans 2

48. What is 0.004 + 0.1 ? 1.0.104 2.0.10 3.0.1 ans 3

49. What is 49 + 1.1 ? 1.50.1 2.50.10 3.50. Sig Figs Review ans 3

50. D. Accuracy = the closeness of a measurement to the actual value