Physics for Scientists and Engineers
Authors: Raymond A. Serway
10th Edition
© 2014 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
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Physics And Measurement
CHAPTER OUTLINE
1.1 Standards Of Length, Mass, And Time
1.2 Matter And Model Building
1.3 Dimensional Analysis
1.4 Conversion Of Units
1.5 Estimates And Order-Of-Magnitude Calculations
1.6 Significant Figures
* An asterisk indicates a question or problem new to this edition.
ANSWERS TO OBJECTIVE QUESTIONS
OQ1.1 The Meterstick Measurement, (A), And (B) Can All Be 4.31 Cm. The Meterstick
Measurement And (C) Can Both Be 4.24 Cm. Only (D) Does Not Overlap.
Thus (A), (B), And (C) All Agree With The Meterstick Measurement.
OQ1.2 Answer (D). Using The Relation
2.54 Cm 1M
1 Ft 12 In 0.304 8 M
1 In 100 Cm
We Find
That
2
0.304 8 M
1 420 Ft2 132 M2
1 Ft
OQ1.3 The Answer Is Yes For (A), (C), And (E). You Cannot Add Or Subtract A
Number Of Apples And A Number Of Jokes. The Answer Is No For (B) And
(D). Consider The Gauge Of A Sausage, 4 Kg/2 M, Or The Volume Of A
Cube, (2 M)3. Thus We Have (A) Yes; (B) No; (C) Yes; (D) No; And (E) Yes.
1
© 2014 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
,
, 2 Physics and Measurement
OQ1.4 41 € 41 € (1 L/1.3 €)(1 Qt/1 L)(1 Gal/4 Qt) (10/1.3) Gal 8 Gallons,
Answer (C).
OQ1.6 The Number Of Decimal Places In A Sum Of Numbers Should Be The Same
As The Smallest Number Of Decimal Places In The Numbers Summed.
21.4 S
15 S
17.17 S
4.003 S
57.573 S = 58 S, Answer (D).
OQ1.7 The Population Is About 6 Billion = 6 × 109. Assuming About 100 Lb Per Person
= About 50 Kg Per Person (1 Kg Has The Weight Of About 2.2 Lb), The Total
Mass Is About (6 × 109)(50 Kg) = 3 × 1011 Kg, Answer (D).
OQ1.8 No: A Dimensionally Correct Equation Need Not Be True. Example: 1
Chimpanzee = 2 Chimpanzee Is Dimensionally Correct.
Yes: If An Equation Is Not Dimensionally Correct, It Cannot Be Correct.
OQ1.9 Mass Is Measured In Kg; Acceleration Is Measured In M/S2. Force = Mass ×
Acceleration, So The Units Of Force Are Answer (A) Kg M/S2.
OQ1.10 0.02(1.365) = 0.03. The Result Is (1.37 0.03) × 107 Kg. So (D) 3 Digits Are
Significant.
ANSWERS TO CONCEPTUAL QUESTIONS
CQ1.1 Density Varies With Temperature And Pressure. It Would Be Necessary To
Measure Both Mass And Volume Very Accurately In Order To Use The
Density Of Water As A Standard.
CQ1.2 The Metric System Is Considered Superior Because Units Larger And Smaller
Than The Basic Units Are Simply Related By Multiples Of 10. Examples: 1
Km = 103 M, 1 Mg = 10–3 G = 10–6 Kg, 1 Ns = 10–9 S.
CQ1.3 A Unit Of Time Should Be Based On A Reproducible Standard So It Can Be
Used Everywhere. The More Accuracy Required Of The Standard, The Less
The Standard Should Change With Time. The Current, Very Accurate
Standard Is The Period Of Vibration Of Light Emitted By A Cesium Atom.
Depending On The Accuracy Required, Other Standards Could Be: The
Period Of Light Emitted By A Different Atom, The Period Of The Swing Of A
Pendulum At A Certain Place On Earth, The Period Of Vibration Of A Sound
Wave Produced By A String Of A Specific Length, Density, And Tension, And
The Time Interval From Full Moon To Full Moon.
CQ1.4 (A) 0.3 Millimeters; (B) 50 Microseconds; (C) 7.2 Kilograms
© 2014 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.