2. Observation, Inference & Measurement
Topic 1:
Observation, Inference & Measurement

4. Observation vs. Inference
Information gained by using the 5 senses.
Example:
* All measurements are observations
Inference-
Interpretation conclusion or explanation based on observations.
Example:
* Predictions are inferences

5. Scientific Notation
A way of writing numbers that are very large or very small.
Step 1: Change the number to a number between 1 and 10 by moving the decimal point.
Step 2: Assign an exponent of 10 equal to the number of places the decimal place was moved.
Example:
4,600,000,000 = 4.6 x 109
= 5.4 x 10-6

6. Measurements-
Defn- Comparing an unknown amount to a known amount.

7. Basic Measurements Measurement Definition Instrument Metric Units
Other Units
Mass
Volume
Length
Temperature
Time
Weight

8. Classification:
Grouping of things based on similar characteristics to make them more meaningful and easier to understand.
Instrument-
Any device used to aid the senses in making observations

9. Brainstorming What weighs more…
A ton of bricks or a ton of marshmallows???
Which is more dense?

10. Density Mass Volume Density = The mass per unit volume. Formula:
Example:
Mass
Volume
Density =

11. “The Density Pyramid”
Examples: M D V

12. Sample Problems
Mass = 34g Density= 8 g/cm3 Volume= Volume= 27cm3 Density =5 g/cm3 Mass=

13. Factors Affecting Density:
Temperature-
As temperature increases, density decreases. (indirect relationship)
Pressure-
As pressure increases, density increases. (direct relationship)
Size and shape do not effect density!!!

14. Most materials have their greatest density in the solid phase
Water is the most dense as a liquid at a temperature of 4o C.
The density of water is 1g/cm3
Objects made of the same material will have the same density

15. Difference from the accepted value
Percent Deviation:
Difference from the accepted value
Accepted value
X 100
% Deviation =
Examples:

16. Classification-
Grouping objects based on similar characteristics.
Instrument-
Any device used to aid the senses in making observations

17. Change When the characteristics or properties of a system are altered.
Cyclic Vs Non- Cyclic

18. Rate of Change Formula: Examples: Change in Field Value Time

19. The temperature at 8 am this morning was 62o
The temperature at 8 am this morning was 62o. At 11am the air temperature was 73o. Calculate the rate of temperature change (include proper units).
The elevation of Mount Matice in 1944 was 11,208 ft. In 2009, the elevation had decreased to 11,194 ft. Calculate the rate of change in elevation during this time. (round to the nearest hundreth and use proper units).

20. Graphing Change
The steeper the slope, the greater the rate of change.

21. Volume Mass Volume Mass
MATERIAL A
Volume
Mass 2 4 3 6 8 12
MATERIAL B
Volume
Mass 1 3 2 6 4 12 5 15

22. Volume Mass Volume Mass
MATERIAL A
Volume
Mass 2 4 3 6 8 12
MATERIAL B
Volume
Mass 1 3 2 6 4 12 5 15

23. MATERIAL A
Calculate the Density represented by the lines plotted on the graph to the right.
MATERIAL B

24. Dynamic Equilibrium-
Situations where change is occurring but overall balance is maintained.
Examples:

25. Metric Conversion Kilo Hecto Deca Deci Centi Milli 7405 mm = meters
Gram
Meter
Liter
Kilo
Hecto
Deca
BASIC
Deci
Centi
Milli
7405 mm = meters
.875 kg = grams

26. Pollution:
Occurs when the concentration of a substance or an energy source becomes high enough to have an adverse (bad) effect on the environment.
As the population density increases, the amount of pollution increases

27. Brainstorm
How would you go about determining the density of a liquid?

28. BONUS:
“Situations where change is occurring but overall balance is maintained.”
What is this the definition of?

29. BONUS:
Explain what will happen to the density of air when the pressure exerted on it is decreased.