SOLUTION MANUAL FOR
Solution Manual For
Physics for Scientists and Engineers: a Strategic
Approach with Modern Physics, Global Edition
5th Edition
1
,CHAPTER 1: Introduction, Measurement, Estimating Responses
To Questions
1. (a) A Particular Person’s Foot. Merits: Reproducible. Drawbacks: Not Accessible To The General
Public; Not Invariable (Could Change Size With Age, Time Of Day, Etc.); Not Indestructible.
(b) Any Person’s Foot. Merits: Accessible. Drawbacks: Not Reproducible (Different People
Have Different Size Feet); Not Invariable (Could Change Size With Age, Time Of Day,
Etc.); Not Indestructible.
Neither Of These Options Would Make A Good Standard.
2. The Number Of Digits You Present In Your Answer Should Represent The Precision With Which
You Know A Measurement; It Says Very Little About The Accuracy Of The Measurement. For
Example, If You Measure The Length Of A Table To Great Precision, But With A Measuring
Instrument That Is Not Calibrated Correctly, You Will Not Measure Accurately.
3. The Writers Of The Sign Converted 3000 Ft To Meters Without Taking Significant Figures Into
Account. To Be Consistent, The Elevation Should Be Reported As 900 M.
4. The Distance In Miles Is Given To One Significant Figure And The Distance In Kilometers Is Given
To Five Significant Figures! The Figure In Kilometers Indicates More Precision Than Really Exists
Or Than Is Meaningful. The Last Digit Represents A Distance On The Same Order Of Magnitude
As The Car’s Length!
5. If You Are Asked To Measure A Flower Bed, And You Report That It Is “Four,” You Haven’t Given
Enough Information For Your Answer To Be Useful. There Is A Large Difference Between A Flower
Bed That Is 4 M Long And One That Is 4 Ft Long. Units Are Necessary To Give Meaning To The
Numerical Answer.
6. Imagine The Jar Cut Into Slices Each About The Thickness Of A Marble. By Looking Through The
Bottom Of The Jar, You Can Roughly Count How Many Marbles Are In One Slice. Then Estimate
The Height Of The Jar In Slices, Or In Marbles. By Symmetry, We Assume That All Marbles Are
The Same Size And Shape. Therefore The Total Number Of Marbles In The Jar Will Be The
Product Of The Number Of Marbles Per Slice And The Number Of Slices.
7. You Should Report A Result Of 8.32 Cm. Your Measurement Had Three Significant Figures. When You
Multiply By 2, You Are Really Multiplying By The Integer 2, Which Is Exact. The Number Of Significant
Figures Is Determined By Your Measurement.
8. The Correct Number Of Significant Figures Is Three: Sin 30.0º = 0.500.
9. You Only Need To Measure The Other Ingredients To Within 10% As Well.
10. Useful Assumptions Include The Population Of The City, The Fraction Of People Who Own Cars,
The Average Number Of Visits To A Mechanic That Each Car Makes In A Year, The Average
Number Of Weeks A Mechanic Works In A Year, And The Average Number Of Cars Each Mechanic
Can See In A Week.
(a) There Are About 800,000 People In San Francisco. Assume That Half Of Them Have Cars. If
Each Of These 400,000 Cars Needs Servicing Twice A Year, Then There Are 800,000 Visits To
Mechanics In A Year. If Mechanics Typically Work 50 Weeks A Year, Then About 16,000 Cars
2
, Would Need To Be Seen Each Week. Assume That On Average, A Mechanic Can Work On 4
Cars Per Day, Or 20 Cars A Week. The Final Estimate, Then, Is 800 Car Mechanics In San
Francisco.
(b) Answers Will Vary.
© 2008 Pearson Education, Inc., Upper Saddle River, NJ. All Rights Reserved. This Material Is Protected Under All Copyright Laws As They
Currently Exist. No Portion Of This Material May Be Reproduced, In Any Form Or By Any Means, Without Permission In Writing From The
Publisher.
3
, Physics for Scientists & Engineers with Modern Physics, 4th Edition Instructor Solutions Manual
11. One Common Way Is To Observe Venus At Sun
Venus
A Time When A Line Drawn From Earth To
Venus Is Perpendicular To A Line
Connecting Venus To The Sun. Then Earth,
Venus, And The Sun Are At The Vertices Of
A Right Triangle, With Venus At The 90º
Angle. (This Configuration Will Result In
The Greatest Angular Distance Between
Earth
Venus And The Sun, As Seen From Earth.)
One Can Then Measure The Distance To
Venus, Using Radar, And Measure The Angular Distance Between Venus And The Sun. From This
Information You Can Use Trigonometry To Calculate The Length Of The Leg Of The Triangle That
Is The Distance From Earth To The Sun.
12. No. Length Must Be Included As A Base Quantity.
Solutions To Problems
1. (a) 14 Billion Years 1.4 1010 years
1.4 1010 Y 3.156 107s 1 Y 4.4 10 s
17
(b)
2. (A) 214 3 significant figures
(b) 81.60 4 significant figures
(c) 7.03 3 significant figures
(d) 0.03 1 significant figure
(e) 0.0086 2 significant figures
(f) 3236 4 significant figures
(g) 8700 2 significant figures
3. (A) 1.156 1.156 100
(B) 21.8 2.18 101
(c) 0.0068 6.8 10−3
(d) 328.65 3.2865 102
(e) 0.219 2.19 10−1
(f) 444 4.44 102
4. (A) (c)
(B)
4
Solution Manual For
Physics for Scientists and Engineers: a Strategic
Approach with Modern Physics, Global Edition
5th Edition
1
,CHAPTER 1: Introduction, Measurement, Estimating Responses
To Questions
1. (a) A Particular Person’s Foot. Merits: Reproducible. Drawbacks: Not Accessible To The General
Public; Not Invariable (Could Change Size With Age, Time Of Day, Etc.); Not Indestructible.
(b) Any Person’s Foot. Merits: Accessible. Drawbacks: Not Reproducible (Different People
Have Different Size Feet); Not Invariable (Could Change Size With Age, Time Of Day,
Etc.); Not Indestructible.
Neither Of These Options Would Make A Good Standard.
2. The Number Of Digits You Present In Your Answer Should Represent The Precision With Which
You Know A Measurement; It Says Very Little About The Accuracy Of The Measurement. For
Example, If You Measure The Length Of A Table To Great Precision, But With A Measuring
Instrument That Is Not Calibrated Correctly, You Will Not Measure Accurately.
3. The Writers Of The Sign Converted 3000 Ft To Meters Without Taking Significant Figures Into
Account. To Be Consistent, The Elevation Should Be Reported As 900 M.
4. The Distance In Miles Is Given To One Significant Figure And The Distance In Kilometers Is Given
To Five Significant Figures! The Figure In Kilometers Indicates More Precision Than Really Exists
Or Than Is Meaningful. The Last Digit Represents A Distance On The Same Order Of Magnitude
As The Car’s Length!
5. If You Are Asked To Measure A Flower Bed, And You Report That It Is “Four,” You Haven’t Given
Enough Information For Your Answer To Be Useful. There Is A Large Difference Between A Flower
Bed That Is 4 M Long And One That Is 4 Ft Long. Units Are Necessary To Give Meaning To The
Numerical Answer.
6. Imagine The Jar Cut Into Slices Each About The Thickness Of A Marble. By Looking Through The
Bottom Of The Jar, You Can Roughly Count How Many Marbles Are In One Slice. Then Estimate
The Height Of The Jar In Slices, Or In Marbles. By Symmetry, We Assume That All Marbles Are
The Same Size And Shape. Therefore The Total Number Of Marbles In The Jar Will Be The
Product Of The Number Of Marbles Per Slice And The Number Of Slices.
7. You Should Report A Result Of 8.32 Cm. Your Measurement Had Three Significant Figures. When You
Multiply By 2, You Are Really Multiplying By The Integer 2, Which Is Exact. The Number Of Significant
Figures Is Determined By Your Measurement.
8. The Correct Number Of Significant Figures Is Three: Sin 30.0º = 0.500.
9. You Only Need To Measure The Other Ingredients To Within 10% As Well.
10. Useful Assumptions Include The Population Of The City, The Fraction Of People Who Own Cars,
The Average Number Of Visits To A Mechanic That Each Car Makes In A Year, The Average
Number Of Weeks A Mechanic Works In A Year, And The Average Number Of Cars Each Mechanic
Can See In A Week.
(a) There Are About 800,000 People In San Francisco. Assume That Half Of Them Have Cars. If
Each Of These 400,000 Cars Needs Servicing Twice A Year, Then There Are 800,000 Visits To
Mechanics In A Year. If Mechanics Typically Work 50 Weeks A Year, Then About 16,000 Cars
2
, Would Need To Be Seen Each Week. Assume That On Average, A Mechanic Can Work On 4
Cars Per Day, Or 20 Cars A Week. The Final Estimate, Then, Is 800 Car Mechanics In San
Francisco.
(b) Answers Will Vary.
© 2008 Pearson Education, Inc., Upper Saddle River, NJ. All Rights Reserved. This Material Is Protected Under All Copyright Laws As They
Currently Exist. No Portion Of This Material May Be Reproduced, In Any Form Or By Any Means, Without Permission In Writing From The
Publisher.
3
, Physics for Scientists & Engineers with Modern Physics, 4th Edition Instructor Solutions Manual
11. One Common Way Is To Observe Venus At Sun
Venus
A Time When A Line Drawn From Earth To
Venus Is Perpendicular To A Line
Connecting Venus To The Sun. Then Earth,
Venus, And The Sun Are At The Vertices Of
A Right Triangle, With Venus At The 90º
Angle. (This Configuration Will Result In
The Greatest Angular Distance Between
Earth
Venus And The Sun, As Seen From Earth.)
One Can Then Measure The Distance To
Venus, Using Radar, And Measure The Angular Distance Between Venus And The Sun. From This
Information You Can Use Trigonometry To Calculate The Length Of The Leg Of The Triangle That
Is The Distance From Earth To The Sun.
12. No. Length Must Be Included As A Base Quantity.
Solutions To Problems
1. (a) 14 Billion Years 1.4 1010 years
1.4 1010 Y 3.156 107s 1 Y 4.4 10 s
17
(b)
2. (A) 214 3 significant figures
(b) 81.60 4 significant figures
(c) 7.03 3 significant figures
(d) 0.03 1 significant figure
(e) 0.0086 2 significant figures
(f) 3236 4 significant figures
(g) 8700 2 significant figures
3. (A) 1.156 1.156 100
(B) 21.8 2.18 101
(c) 0.0068 6.8 10−3
(d) 328.65 3.2865 102
(e) 0.219 2.19 10−1
(f) 444 4.44 102
4. (A) (c)
(B)
4
