1. Unit 1: Measurements, Accuracy, and Precision Notes

2. Qual vs. Quant Key Concept 1
Qualitative data: deals with descriptions.
Quantitative data: deals with numbers
Examples
Room Number:
What was an example from our Mass and Change Lab of quantitative data?
T/F Did the Mass and Change Lab have any qualitative data?

3. Units
Significant Figures: Crash Course
Stop at 3:45
Système Internationale d'Unités (SI) is an internationally agreed upon system of measurements.
A base unit is a defined unit in a system of measurement that is based on an object or event in the physical world, and is independent of other units.

4. Units (cont.)
Key Concept 2

5. Comparing Units of Volume
Key Concept 3: Volume measures the amount of space an object takes up, and is a derived SI unit.
Key Concept 4: The volume of a cube is V=length x width x height
How do you determine the volume of objects?

6. Comparing Units of Volume
Key Concept 6: Volume can be measured in cubic centimeters (cm3) using a ruler or in milliliters (mL) by using a graduated cylinder.
Key Concept 5: The volume of a cylinder is V= πr2 x height
What would the units be? Are they any other units that volume is measured in?

7. mL and cm3 Quick Activity
Goal: Compare the volume that are calculated using a rule with those measured using a graduated cylinder.
mL and cm3

8. How can you minimize error?
Ask Kids

9. Class Data Cube Cylinder cubic centimeters (cm3) Milliliter (mL)
Ask Kids

10. How are mL and cm3related?
Quick Activity
Goal: Compare the volume that are calculated using a rule with those measured using a graduated cylinder.
How are mL and cm3related?

11. Closure Type: Socrative Exit Poll
Volume is not concerned an SI unit. How did scientist choose to define volume?

13. Yesterday
Measurements can be:
Qualitative
Quantitative
SI Units

14. Today
SI Units
Important of Units
Sig Figs
Review Scientific Notation
Accuracy vs. Precision

15. SI Units- Length
1792: French established a new system of weights and measures
1 m = distance from N. pole to equator ten-million
Then, in the 1870s: 1 m = distance between fine lines on Pt-Ir bar
Accurate copies sent around the world
Time and length linked

16. SI- Length The SI base unit for length is the meter (m).
A meter is equal to the length of the path travelled by light in a vacuum during a time interval of 1⁄299,792,458 of a second.

17. SI- Mass
The SI base unit of mass is the kilogram (kg), about 2.2 pounds

18. SI- Temperature The SI base unit of temperature is the kelvin (K).
Zero kelvin is the point where there is virtually no particle motion or kinetic energy, also known as absolute zero.
Two other temperature scales are Celsius and Fahrenheit.

19. Importance of Units
In 1999 the United States lost the Mars Climate Orbiter as it approached Mars.
The loss of the $125 million spacecraft was due to scientists confusing English units and metric units.

20. Importance of Units
The spacecraft team in Colorado used English units of pounds of force to describe small forces needed to adjust the spacecraft’s orbit. The data was shipped via computer, without units, to the NASA’s Jet Propulsion Lab (JPL) , where the navigation team was expecting the to receive the data in metric measure.

22. Importance of Units
A train of length 2, weighing 200, travels from Denver to Santa Fe at 15. How long did the trip take? 

23. NO NAKED NUMBERS Importance of Units
This brings up the issue of units. In your math class, numbers by themselves are fine to work with, but in science a number without units is pretty useless.
NO NAKED NUMBERS
“NO STREAKING”

24. “We can only be as accurate as our weakest measurements”.
Importance of Units
“We can only be as accurate as our weakest measurements”.

25. Today
SI Units
Important of Units
Sig Figs
Review Scientific Notation
Accuracy vs. Precision

26. Often, precision is limited by the tools available.
Significant Figures
Often, precision is limited by the tools available.
Key Concept 7: The significant figures of a number are those digits that carry meaning contributing to its precision. When measuring significant figures include all known digits plus one estimated digit.

27. Learning Check
What is the length of the wooden stick?

28. Learning Check
Record the measurement using significant figures.

30. Significant Figures (cont.)
Rules for significant figures
Rule 1: Nonzero numbers are always significant.
Rule 2: Zeros between nonzero numbers are always significant.
Rule 3: All final zeros to the right of the decimal are significant.
Rule 4: Placeholder zeros are not significant. To remove placeholder zeros, rewrite the number in scientific notation.
Rule 5: Counting numbers and defined constants have an infinite number of significant figures.
Pass out Box and Dot and have students complete the problems and submit some through Socrative.

31. Shoulder Partner Practice SF’s

32. Meter Stick
Use the 4 sided meter stick and measure an object varies ways

33. Quick Demo
I need two groups of three volunteers that can measure using a meter stick (cm).
Number of trails
Length of tape in cm 1 2 3

34. Scientific Notation
5.67 x 105         coefficient        base       exponent    In order for a number to be in correct scientific notation, the following conditions must be true:
The coefficient must be greater than or equal to 1 and less than 10.
The base must be 10.
The exponent must show the number of decimal places that the decimal needs to be moved to change the number to standard notation. 

35. Scientific Notation (cont.)
The number of places moved equals the value of the exponent.
The exponent is positive when the decimal moves to the left and negative when the decimal moves to the right.
800 = 8  102
=  10–5

36. Today
SI Units
Important of Units
Sig Figs
Scientific Notation
Accuracy vs. Precision

37. Accuracy and Precision
Key Concept 8: Accuracy refers to how close a measured value is to an accepted value.
Key Concept 9: Precision refers to how close a series of measurements are to one another.
Pin the mitten on the kitten

39. Today SI Units Important of Units Sig Figs Scientific Notation
Accuracy vs. Precision
You have Unit 1A and Unit 1B Practice Problem.
Unit 1 Prove It Quiz is 26th or 27th