MEASUREMENT
Chapter 1 is important because all quantitative knowledge about our physical
environment is based on measurement. Some chapter sections have been reorganized and
rewritten for clarity. The 1.2 Section, “Scientific Investigation,” introduces the student to the
procedures for scientific investigation. Major terms such as experiment, law, hypothesis,
theory and scientific method are introduced. The idea that physical science deals with
quantitative knowledge should be stressed. It is not enough to know that a car is going
“fast”; it is necessary to know how fast.
A good understanding of units is of the utmost importance, particularly with the
metric-British use in the United States today. The metric SI is introduced and explained.
Both the metric and the British systems are used in the book in the early chapters for
familiarity. The instructor may decide to do examples primarily in the metric system, but
the student should get some practice in converting between the systems. This provides
knowledge of the comparative size of similar units in the different systems and makes the
student feel comfortable using what may be unfamiliar metric units. The Highlight, “Is Unit
Conversion Important? It Sure Is,” illustrates the importance of unit conversion.
The general theme of the chapter and the textbook is the students’ position in his or
her physical world. Show the students that they know about their environment and
themselves through measurements. Measurements are involved in the answers to such
questions as, How old are you? How much do you weigh? How tall are you? What is the
normal body temperature? How much money do you have? These and many other technical
questions are resolved or answered by measurements and quantitative analyses.
DEMONSTRATIONS
Have a meter stick, a yardstick, a timer, one or more kilogram masses, a one-liter beaker or
a liter soda container, a one-quart container, and a balance or scales available on the
instructor’s desk. Demonstrate the comparative units. The meter stick can be compared to
the yardstick to show the difference between them, along with the subunits of inches and
,centimeters. The liter and quart also can be compared. Pass the kilogram mass around the
classroom so that students can get some idea of the amount of mass in one kilogram. Mass
and weight may be compared on the balance and scales.
When discussing Section 1.6, “Derived Units and Conversion Factors,” have class
members guess the length of the instructor’s desk in metric and British units. Then have
several students independently measure the length with the meter stick and yardstick.
Compare the measurements in terms of significant figures and units. Compare the averages
of the measurements and estimates. Convert the average metric measurement to British
units, and vice versa, to practice conversion factors and to see how the measurements
compare.
Various metric unit demonstrations are available from commercial sources.
ANSWERS TO MATCHING QUESTIONS
a. 19 b. 13 c. 21 d. 14 e. 15 f. 8 g. 10 h. 2 i. 21 j. 1 k. 9 l. 4 m. 18 n. 6 o. 11 p.
3 q. 20 r. 16 s. 22 t. 7 u. 23 v. 17 w. 5
ANSWERS TO MULTIPLE-CHOICE QUESTIONS
1. c 2. b 3. d 4. b 5. b 6. b 7. d 8. c 9. d 10. c 11. d 12. c 13. a
ANSWERS TO FILL-IN-THE-BLANK QUESTIONS
1. biological 2. hypothesis 3. scientific method 4. sight 5. limitations 6. greater than
7. shorter 8. fundamental 9. time or second 10. one-millionth, 10 -6 11. liter
12. mass
ANSWERS TO SHORT-ANSWER QUESTIONS
1. An organized body of knowledge about the natural universe by which knowledge is
acquired and tested.
2. Physics, chemistry, astronomy, meteorology, and geology.
3. Observations and Measurements.
4. Hypothesis.
5. A law is a concise statement about a fundamental relationship of nature. A theory is a
well-tested explanation of a broad segment of natural phenomena.
,6. That phenomena must be investigated, not speculated.
7. Sight, hearing, touch, taste, and smell.
8. They have limitations and can be deceived.
9. (a) No. (b) Yes. (c) Good luck. (Use a couple of straight edges to determine.)
10. They are the most basic quantities of which we can think.
11. A fixed and reproducible value.
12. A group of standard units and their combinations.
13. km/hour
14. Yes, officially adopted in 1899.
15.Kilogram, a platinum-iridium cylinder.
16. Mass. Weight varies with gravity.
17. Meter-kilogram-second, International System of Units, centimeter-gram-second.
18. Base 10 easier to use (factors of 10).
19. mega- (M), kilo- (k), centi- (c), milli- (m)
20. Mass of a cubic liter of water.
21. Cubic meter.
22. kg, m, s, and C (electric charge).
23. The compactness of matter.
24. It is given a new name.
25. No. An equation must be equal in magnitude and units.
26. Yes. And it could be confused with “meters” instead of “miles.”
27. To express measured numbers properly.
28. By reading a measurement value from an instrument and rounding according to the
general rules.
29. Two.
, ANSWERS TO VISUAL CONNECTION
a. meter, b. kilogram, c. second, d. mks, e. foot, f. pound, g. second, h. fps
ANSWERS TO APPLYING-YOUR-KNOWLEDGE QUESTIONS
1. Scientific laws explain nature, not to regulate society (legal laws), and scientific laws
do not compel, just describe.
2. The liter is larger than the quart, and the kilogram is larger than the pound. However,
the kilometer itself is shorter than the mile.
3. Intrinsic properties are invariant. Kilogram cylinder and meterstick subject to wear,
dirt, and change.
4. A liter, because it is larger than a quart.
5. (a) No, gold would weigh about 20 times more. (b) Solving for mass from the density
equation, this would be 19320 g or 19.32 kg. No playing catch, as weight is about 45 lb.
(1 kg = 2.2 lb).
6. 1 m = 3.28 ft. 830 m (3.28 ft/m) = 2.72 x 103 ft; 508 m (3.28 ft/m) = 1.67 x 103 ft.
Δ = 1.05 x 103 ft
ANSWERS TO EXERCISES
1. 10,000 cm or 105 cm
2. 2 x l03 Mb
3. 106 mm3
4. 1 m3 = 103 L. 1 m3 = 102 cm x 102 cm x 102 cm = 106 cm3 (1 L/103 cm3) = 103 L = 1000 L.
5. 0.50 L (1 kg/L) = 0.50 kg = 500 g
6. 25 cm 25 cm 35 cm = 22 103 cm3 or mL = 22 L and 12 L (1 kg/L) = 12 kg = 12,000 g
7. (a) 0.55 Ms = 0.55 106 s (b) 2.8 km = 2.8 103 m (c) 12 mg = 12 10–3 g = 1.2 10–6 kg
(d) 100 cm = 1.00 m
8. (a) 40 Mb (b) 572.2 mL (c) 540.0 x 102 cm (d) 5.5 kilobucks
9. 6 ft 5 in. = 77 in (2.54 cm/in.) = 196 cm = 1.963 m
10. 6 ft, 7 in.
11. Yes, to two significant figures