Travers
PS II CP
Meaningful Metrics Review
Overview of Metrics and Measurement Unit: Mrs. Travers (PS II - CP)
Text Reference: Chapter 1 (Section 1.2), CPO Text, Describing the Physical
Universe
Terms to Know from Text and Classroom Lecture and Activities:
observation
inference
Accuracy
Precision
Data
Significant Figures
Qualitative data
Quantitative data
Metric Pre-fixes
Percent Error
Performance Based Standards (what you should be able to do at the end of
this unit):
1. I can distinguish between observations (data) and inferences
(conclusions)
2. I know the difference between accuracy and precision of a single
measurement.
3. I can calculate the percent error between two values to determine
the accuracy of a measurement.
4. I can record a measurement from a measuring device (e.g. a ruler,
scale) with the correct amount of precision (i.e. significant digits)
5. I can identify the correct number of significant figures given a
measurement.
6. I can do calculations using measurements and provide answers with
the correct number of significant digits.
7. I can readily perform metric conversions between measurements
having prefixes milli-, centi-, and kilo-.
8. I know which unit is bigger when comparing English units to metric
units: e.g. pound vs. gram; centimeter vs. inch; liter vs. gallon; mile vs.
kilometer.
9. I can convert values into scientific notation correctly and add,
subtract, multiply and divide values in scientific notation correctly.
10. I can use and show factor label method (FLM) in doing conversions
from one set of units to another.
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Percent Error
1. A student measures the volume of a 2.50 liter container to be 2.38 liters.
What is the percent error in the student's measurement?
Accuracy vs. Precision
2a. Suppose a GPS (Global Positioning System) which measures your position on
earth, is not calibrated correctly. You take 3 readings at the same place and they
are all close together but 14 miles from your actual position. Explain your results in
terms of precision and accuracy.
b.What is the difference in the measurements 4 vs 4.00 vs 4.00000? In terms of
taking measurements, explain why we use significant figures.
3.
Measure the length of object below given the measuring device provided.
Mixed Review
4. What is the difference between an observation and an inference? Write an
example of each.
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5. Convert the following:
12.3 cm to m
45 hg to g
5.67 km to m
6. What is the meaning of the prefix kilo-?
7.
centi-?
Give two conversion factors from English units to metric units.
8. Which is bigger?
A mile or a kilometer?
A liter or a gallon?
A kg or a pound?
9. Convert the following using FLM. Show your work.
34.5 ft to inches
120 pounds to grams (454 grams = 1 pound)
10. How many significant figures are in the following:
0.005 cm
0.50 cm
0.5 cm
0.500 cm
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5000cm
11. Give answer with correct number of s.f.
654g/2.2 mL =
12. Convert to scientific notation
600,100 m
0.00980 g
5430.0 kg
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