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Mistakes in How Things Work: the Physics of Everyday Life, 3rd Edition

Typographical Errors and Wording Mistakes:

Page 21, Figure 1.2.7: Degree symbol is missing after "45". (submitted)

Page 50: First Paragraph: "on p. 43" -> "on p. 9". (submitted)

Page 71: Second Box: "on p. 28" -> "on p. 24". (submitted)

Page 101, Figure 3.3.3: The label "Boy's path" has an unwanted character in it. (submitted)

Page 105, First Full Paragraph, Line 7: "tra-veling" -> "traveling". (submitted)

Page 119, Sixth Full Paragraph, Line 4: "lets you to use" -> "lets you use". (submitted)

Page 123, Third Full Paragraph, Line 2: "depends the nozzle's" -> "depends on the nozzle's". (submitted)

Page 127, Check Your Figures #1: "for answers, see page 135" -> "for answers, see page 136". (submitted)

Page 140, Opening Figure: The "Basket support cables" are essentially invisible.

Page 133, First Full Paragraph, Line 1: "Newtonian's law" -> "Newton's law". (submitted)

Page 169, Figure 6.1.1: "are the results of" -> "are the result of". (submitted)

Page 183, Figure 6.2.10: Degree symbols are missing after "35" and "45". (submitted)

Page 200, Question 9: "because near the bridge's" -> "because, near the bridge's" (submitted)

Page 219, 2nd Full Paragraph, Line 3: "molecules" -> "molecule".

Page 245, 3rd Full Paragraph, Line 2: "Eqs. 8.1.1" -> "Eq. 8.1.2". (submitted)

Page 282, Aside, Line 4: "to explain of the intricate" -> "to explain the intricate".

Page 349, Figure 11.1.4: Left image is (a), right image is (b).

Page 367, Figure 11.2.10: "High-voltage cross-couuntry lines" -> "High-voltage cross-country lines".

Page 392, Figure 12.1.2: Part (c) is missing. (submitted)

Page 399, Figure 12.1.7: Labels (a), (b), and (c) are not italicized. (submitted)

Page 403, Last Full Paragraph, Line 2: "smoothes" -> "smooths". (submitted)

Page 452, Figure 14.1.10: Top image is (a), bottom image is (b).

Page 462, 2nd to last full paragraph, bottom line: "tube's color charges until" -> "tube's color changes until".

Page 479, Figure 15.1.2: Left image is (a), right image is (b).

Page 512, Figure 16.1.7: Left image is (top), right image is (bottom).

Page 540, Entry "electrical conductor" is out of alphabetical order.

Mistakes in How Everything Works: Making Physics out of the Ordinary

Typographical Errors and Wording Mistakes:

Page 13, Aside #2: "air resistance increases speed" -> "air resistance increases with speed". (submitted)

Page 26, First Full Paragraph, Line 6: "in the direction that force" -> "in the direction of that force". (submitted)

Page 28, Second to Last Full Paragraph, Line 2: "perpendicular its surface" -> "perpendicular to its surface." (submitted)

Page 55, Last Full Paragraph, Line 2: "in northward direction" -> "in the northward direction". (submitted)

Page 56, Third Full Paragraph, Line 4: "pass" -> "passed". (submitted)

Page 57, Figure 2.3.3: "an airbag reducing the impact force" -> "an airbag reduces the impact force". (submitted)

Page 58, Last Full Paragrah, Last Line: "wood" -> "wood or stone". (submitted)

Page 68, First Paragraph: "the middle a Roberval balance" -> "the middle of a Roberval balance". (submitted)

Page 75, 3rd Paragraph, Line 4: "same amount the" -> "same amount that the"

Page 93, Seventh Full Paragraph, Line 4: "lets you to use" -> "lets you use". (submitted)

Page 98, First Full Paragraph, Line 2: "depends the nozzle's" -> "depends on the nozzle's". (submitted)

Page 105, Last Full Paragraph, Line 1: "Newtonian's law" -> "Newton's law". (submitted)

Page 115, 2nd Full Paragraph, Line 3: "move South" -> "moves South"

Page 120, 4th Full Paragraph, Line 2: "Fig. 4.4.5" -> "Fig. 4.4.6"

Page 149, Figure 6.1.1: "are the results of" -> "are the result of". (submitted)

Page 156, Figure 6.1.7: "water out" and "water in" are reversed

Page 159, 3rd Paragraph, Line 5: "side another will" -> "side with one another will".

Page 245, 4th Full Paragraph, Line 2: "Eqs. 8.1.1" -> "Eq. 8.1.2". (submitted)

Mistakes in How Things Work: the Physics of Everyday Life, 2nd Edition

Conceptual Errors, Flaws, or Omissions:

Page 10, Third Full Paragraph: One newton is the weight of about 18 US quarters, not the weight of about 10 US quarters, as printed in the book. -- Thanks to Meg Noah for pointing this mistake out to me.

Page 172, First Full Paragraph: Heating of air is not the only reason for the increasing pressure*volume of the gas passing through the jet engine. Combustion of fuel into smaller molecules increases the number of gas particles and thus increases pressure*volume. – thanks to Bob Hubel for finding this mistake.

Page 184, Problem 11: Question omits two crucial pieces of information: The radius of the earth is 6378 kilometers and the distance between the earth and the moon is 384,400 kilometers from center to center. Another item could also be useful: The mass of the earth is 5.97 x 1024 kilograms. There are at least two different ways to use those values to answer the question. – thanks to Bob Hubel for finding this mistake.

Page 222, Check Your Understand #1, Answer: This answer and explanation assume no effects due to air. Air resistance would convert some of the ball’s ordered energy into thermal energy and warm the ball. – thanks to Bob Hubel for finding this mistake.

Page 486, Definition of Newton: One newton is the weight of about 18 US quarters, not the weight of about 10 US quarters, as printed in the book. -- Thanks to Meg Noah for pointing this mistake out to me.

Typographical Errors and Wording Mistakes:

Page vii-xvi: Table of Contents formatting is imperfect. Blue sections have inconsistent font and tab.

Page 32, Section 1.2, CYU #1, Why: "astronaut" has only one "s".

Page 33, Section 1.3, Why #2: The equation is missing a final "."

Page 58, Last Normal Paragraph, 3-to-last-line: "break to a stop" should be "brake to a stop"

Page 62, Paragraph 5, Last Sentence changed to: “Like a bug being hit by an automobile windshield, your bumper car does most of the accelerating.”

Page 69, Important Laws 4 through 7: All the equation numbers should begin with 2.3 rather than 2.2.

Page 94, Figure 3.3.3: There is a spurious red arrow just above the (b) label. It should be removed from the figure.

Page 122, Paragraph 2: There are 5 instances of the square-root of 2 that were somehow mangled in the printing.

Page 122, Last Pagaraph, Line 6: hot air balloon should be hot-air balloon.

Page 140, Section 4.2 – 1. Why, 2nd Equation: 1000 kg/m3.9.8 m/s2 should be 1000 kg/m3·9.8 m/s2.

Page 142, Problem 5: “If you seal a rigid container of air at room…”

Page 156, Figure: Spin vector should point downward, not upward.

Page 176: Gravitational constant is 6.6720 x 10-11 N-m2/kg2 (the minus sign in the exponent is missing in the book).

Page 181, Check Your Figure Answer #1, Second Equation: there is an extra right parenthesis after 0.80.

Page 181, Check Your Figure Answer 5.3 #1, Why: Eq. 5.3.1 is used, not Eq. 4.3.1.

Page 219, New Caption for Figure 6.4.4: “This cut-away view of a BMW automobile engine shows the six pistons arranged in a single row. The cylinders have been omitted from the drawing.”

Page 224, Check Your Figures #1: The correct answer is 524 Watts, not 262 Watts.

Page 236, Figure 7.1.7: Photograph is upside-down (doesn’t match caption).

Page 243, Check Your Understanding #3: Should end with: "turned faster or with less tension. Why?"

Page 257, Exercise 2: Added at the end: (Neglect the rack’s own mass.)

Page 279, Last Paragraph, 3rd Word: "The copier than transfers" -> "The copier then transfers"

Page 318, Figure 9.3.10: Tape motion vector should be motion purple (as in Figure 9.3.9).

Page 311, Paragraph 3, Last Line: … while Europe has a 230-V standard.

Page 313, Paragraph 1, 4th Line: … about 331 m/s.

Page 321, Exercise 3: “to the insulated fence wire.” -> “to the fence wire, which is insulated from the earth.”

Page 324, Case 1, Last Line of Intro: In Europe, the final voltage is 230 V.

Page 324, Case 1, Part d, Line 3: “in the 20-V secondary” -> “in the 120-V secondary”

Page 335, Figure 10.1.9: Labels (a) and (b) are missing from line art.

Page 346, Figure 10.2.10: "dyamic memory" -> "dynamic memory"

Page 348, CYU #4 – Why, Line 3: “half of each power-line cycle when”

Page 349, CYU #1 – Why, Line 1: “Binary 10000001 contains” (one zero was accidentally omitted)

Page 349, Exercise 5, Line 5: “6-V resistor” -> “6-Ω resistor”

Page 349, Exercise 7, Line 2: “6-V resistor” -> “6-Ω resistor”

Page 368, Paragraph 1, Last Line: “running more additional cables.” -> “running additional cables.”

Page 407, Check Your Understanding #5 on Left, Why, First Line: “from a horizontally polarized surface” -> “from a horizontal surface”

Page 494, Chapter 2, Problem 1 solution: “122.5 N·m.”

Page 496, Chapter 5, Problem 9 solution: “About 0.76 m/s” -> “About 0.076 m/s”

Page 498, Chapter 9, Problem 5 solution: “Each battery in this problem supplies 3 W.

Mistakes in How Things Work: the Physics of Everyday Life, 1st Edition

Conceptual Errors, Flaws, or Omissions:

Page 113, Paragraph 1: While Fig. 2.3.7 is correct, the text refering to that figure is incorrect. The paragraph should read:

  • "Halfway up the loop-the-loop, your acceleration is inward and downward, so the fictitious force you experience is outward and upward (4). Your apparent weight is still much more than your weight and is directed outward. You feel pressed into your seat, and the car itself is pressed against the track (Fig. 2.3.8)."

Page 115, CYU #2, Why: "...feel a huge 'centrifugal force' outward." -> "...require a huge centripetal force inward."

Page 185, Fig. 4.3.5: The middle velocity vectors should be longer because the velocity of the airstream remains high almost to the surface of the ball.

Page 190, Fig. 4.3.14: The figure should indicate that the Frisbee is heading toward the left.

Page 190, Paragraph 3: This paragraph mistakenly implies that the pressures and flow velocities are uniform above and below the Frisbee. While there is initially no significant lift on the Frisbee, the pressures and flow velocities are not uniform.

Page 195, Section "Airplane Wings": This section reverses cause and effect--in fact, the air flowing over a lifting wing speeds up because the pressure over that wing is less than the ambient pressure (and not the other way around). This pressure drop is caused by curvature in the airstream--as the airflow over a upward-tilted or convex wing curves downward to follow the wing's surface, the air accelerates downward. This downward acceleration must be caused by a pressure imbalance--the pressure near the wing's upper surface is lower than the ambient pressure. It is this diminished pressure just above an airplane wing that causes the airflow over the wing to speed up. A similar downward curvature occurs below the lifting wing, producing an elevated pressure just below the wing's lower surface. While there are points along both the upper and lower airflows that have reversed curvature and pressure, there is an overall upward lift force on the wing. Moreover, the airflows over and under a lifting wing both curve downward overall and leave the wing with a net downward component to their velocities.

Page 195, Section "Airplane Wings", Paragraph 4: This paragraph states that the flow over and under the wing must rejoin at the trailing edge so that portions of air that are separated at the leading edge rejoin perfectly at the trailing edge. This observation is simply incorrect. Portions of air flowing over the wing while it is experiencing lift always arrive at the trailing edge before portions of air flowing under the wing.

Page 220, Paragraph 4: "...escape velocity follows a parabolic orbital path..." -> "...escape velocity follows a hyperbolic orbital path..."

Page 227, Paragraph 2: "is possible only with two wheeled vehicles" -> "is possible only with vehicles having fewer than three wheels".

Page 277, Paragraph 3, Line 3: "only about 5% of the thermal radiation" -> "only about 12% of the thermal radiation"

Page 278, First Line: "before most of their thermal radiation would be visible." -> "before less than 50% of their thermal radiation would be infrared."

Page 278, Last Paragraph: "'s surrounded by..." -> "'s usually surrounded by..."

Page 278, Last Paragraph: "...which is mostly argon..." -> "...which is mostly argon and nitrogen..."

Page 326, Section "Why Ice Is Slippery": This section omits sliding friction as a key source of ice's slipperiness, when that is in fact the case. Heating due to sliding friction causes surface melting in ice and the layer of liquid water that forms then lubricates the ice.

Page 340, Paragraphs 3-5: The quartz crystal used in most electronic timepieces is not a flat disk, as indicated in the book. Instead, it is actually cut in the shape of a tiny tuning fork. This tuning fork is metalized and then its frequency is adjusted with a laser by vaporizing away some of the metal.

Page 362, Section "The Tide": This section omits many complications associated with the tide, including phase shifts, the tilt of the earth's axis, horizontal gravitational forces on the water in many locations, and so on. In short, it is perhaps overly simplistic.

Page 413, Figure 12.1.3: The two pictures should be reversed to match the caption more directly (closed on the left, open on the right).

Page 413, Paragraph 1 in new subsection: "with each electron completing the journey many thousands of times per second." -> "with each electron completing the journey over and over again." (Note: Because the carrier densities in metals are extremely high, the carrier drift velocity is quite low even in a metal that is carrying a large current density. My failure to understand this low drift velocity introduced subtle inaccuracies in other parts of the text; flaws that I will address in any subsequent edition of the book).

Page 424, Paragraph 6: "The champions of alternating current were Nikola Tesla (1856--1943), a Croatian-American inventor, and George Westinghouse (1846--1914), an American inventor and industrialist." -> "The champion of alternating current was Nikola Tesla (1856--1943), a Serbian-American inventor, who was backed financially by the American inventor and industrialist George Westinghouse (1846--1914)."

Page 494, Last Paragraph: This paragraph incorrectly implies that electric charge can actually move from the antenna tip to its base in 1/4 of a cycle and that this charge moves at the speed of light. While current does travel at or near the speed of light, the charged particles themselves do not. It's the relative distributions of the positive and negative charges within the antenna that produce the apparent charge motion up and down the antenna.

Page 494-495: The book mistakenly assumes that all radio transmissions are vertically polarized. In fact, television broadcasts have historically been horizontally polarized and are now often right-hand circularly polarized. Only a horizontally polarized component is required. The same is true for FM broadcasts--only a horizontally polarized component is required. While actual FM broadcasts are now typically right-hand circularly polarized, other circular polarizations are also permitted. That leaves only AM transmissions as vertically polarized and there is no requirement on that either. It's just easier to use vertical antennas with long-wavelength AM transmissions so that the transmissions are typically vertically polarized.

Typographical Errors and Wording Mistakes:

Page vi, Titles: "Electrical Power Distribution" -> "Electric Power Distribution"

Page vi, Titles: "Electrical Power Generation" -> "Electric Power Generation"

Page vi, Titles: "CD Players" -> "Compact Disc Players"

Page 25, Paragraph 4, Line 3: "while some else" -> "while someone else"

Page 52, Paragraph 3, Line 5: "when isn't moving?" -> "when it isn't moving?"

Page 80, Paragraph 2, Line 10: "in-direction" -> "in direction"

Page 93, Line 5: "bean bag" -> "beanbag"

Page 138, Exercise 25: "defuse" -> "diffuse" (twice)

Page 138, Problem 9: "upward orce" -> "upward force"

Page 143, Paragraph 4: "steady-state flow" is in boldface 3 times, rather than just once.

Page 158, Paragraph 1, Line 2: "verified" should be bold face.

Page 158, Paragraph 2, Line 1 & 5: "balls and air" -> "balls, birdies, and Frisbees"

Page 164, Paragraph 3: "moves in a circle above a central cavity." -> "moves in a circle about a central cavity."

Page 166, Fig. 4.1.6: "water out" and "water in" are reversed.

Page 175, Paragraph 3, Line 4: "1982 explosion of Mount St. Helens" -> "1980 explosion of Mount St. Helens"

Page 188, Fig. 4.3.12: The drawings of the Magnus and Wake Deflection Forces are reversed

Page 196, Last Paragraph, Line 2: "wings' angle of attack" -> "wing's angle of attack"

Page 206, Paragraph 3, Line 1: "balls and air" -> "balls, birdies, and Frisbees"

Page 207, Case 5, Part a: "What force exerts the torque that makes the ball rotate?"

Page 220, Line 2: "At 35,900 km (22,300)" -> "At 35,900 km (22,300 miles)"

Page 226, Last Paragraph, Line 6: "contact force" -> "support force"

Page 227, Fig. 5.2.5: "contact force" -> "support force" (occurs twice)

Page 227, Paragraph 2, Line 7: "tip it over it" -> "tip it over"

Page 251, (throughout Section 6.1): "wood stove" -> "woodstove"

Page 251, Experiments to Do, Line 2: "were does this" -> "where does this"

Page 254, Sidebox "Baveria" -> "Bavaria"

Page 278, Check Your Understanding #1: Title is missing

Page 294, Paragraph 1, Line 4: "to transfer of heat" -> "to transfer heat"

Page 305, Paragraph 1, Line 7: "marvels of the thermal physics" -> "marvels of thermal physics"

Page 306, Paragraph 4, Line 5: "heat pump" -> "heat engine"

Page 309, Paragraph 4, Line 2: "motion in rotary" -> "motion into rotary"

Page 326, Title "Why Ice Is Slippery": The "Is" should be lowercase

Page 334: "time-keeper" -> "timekeeper" (throughout section)

Page 335, Line 4: "with it motion." -> "with its motion."

Page 336, Paragraph 4, Line 5: "flag poles." -> "flagpoles."

Page 340, Paragraph 4, Line 5: "object's masses" -> "objects' masses"

Page 350: "Horse hair" -> "Horsehair"

Page 352, Paragraph 2, Line 7: "pipe's center. (Fig. 9.2.9)" -> "pipe's center (Fig. 9.2.9)."

Page 365, Paragraph 2, Line 5: "It's kinetic energy" -> "Its kinetic energy"

Page 366, Paragraph 3, Line 7: "depends the wave's" -> "depends on the wave's"

Page 367, Paragraph 2, Line 2: "there is not be enough" -> "there is not enough"

Page 380, Paragraph 5, Line 8: "precedes" -> "proceeds"

Page 387, Paragraph 4, Line 3: "after is discoverer" -> "after its discoverer"

Page 408, Case 4, Part a: "spring-load mass" -> "spring-loaded mass"

Page 412, Paragraph 5, Line 8: "on the left side of Fig. 12.1.3" -> "on the right side of Fig. 12.1.3"

Page 413, Paragraph 6, Line 7: "on the the right side of Fig. 12.1.3" -> "on the left side of Fig. 12.1.3"

Page 486, Exercises 8 & 9: Interchanged (#8 is answered as though it were #9)

Page 495, Line 3: "were people are most likely" -> "where people are most likely"

Page 566, Title "The Physics of Photographic Cameras and Projectors" -> "The Physics of Cameras"

Page 689, Section 5.1: Solutions to the odd-numbered problems are missing.

Page 690, Section 7.2: "7.1" -> "7.2" (Section heading is doubled)

Rewording Questions:

Page 75, Case 18, Parts d & e: "500 m tall hill" -> "500 m tall hill (500 m high in altitude)"

Page 76, Case 22, Part c: "a narrow wooden peg" -> "a miniature bowling pin"

Page 248, Case 9, Part c: A person who is riding forward on a two-wheeled bicycle must lean left while making a turn toward the left. Does a person who is riding forward on a unicycle also have to lean left during a left turn?

Page 248, Case 9, Part d: While a unicycle doesn't exhibit dynamic stability the way a two-wheeled bicycle does, there is a way to give it dynamic stability. If you spin the unicycle extremely rapdily about its vertical axis, it will act like a toy top and won't fall over for a very long time. (Unfortunately, it's hard to ride this way.) While gravity will exert a torque on this spinning unicycle about its point of contact with the ground if its axis isn't perfectly vertical, the unicycle doesn't simply fall over. Instead, its axis of rotation changes directions. What is this behavior an example of?

Page 318, Case 5, Part f: As the result of this compression and decompression process, heat was transferred from where to where?

Mistakes in The Instructor's Manual for How Things Work

Conceptual Errors, Flaws, or Omissions:

Page 378, Answer to "Why are there dimples...", Line 4: The claim that a ball that experienced only laminar airflow would experience no air resistance is misleading. The ball experiences no pressure drag but it does experience viscous drag.

Typographical Errors and Wording Mistakes:

Page 342, Problem 18, choice a: "...exerting on the box..." -> "...exerting on the file cabinet..."

Page 382, Answer to "Please explain...", Line 3: "while the top of the wheel" -> "while the bottom of the wheel."

Please report any other errors you find to Lou Bloomfield at!

Last Updated March 13, 2009
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