### 4th Edition Errata (earlier editions below)

Ch. 1 answer to checkpoint 6 (p. 44): Part (a) is .

Ch. 1 answer to checkpoint 15 (p. 44): Part (a) is kg m/s.

Ch. 1 prob. P28 (p. 40): Answer to part (a) is .

Ch. 1 prob. P36 (p. 40): Answer to part (d) is .

Ch. 1 prob. P42 (p. 41): Answer is .

Ch. 1 prob. P53 (p. 41 and A-1): Answer is kg m/s.

Ch. 1 prob. P61 (p. 42 and A-1): Answer is kg m/s.

Ch. 1 prob. P63 (p. 42 and A-1): Answer is kg m/s. Also, the problem statement states that you don’t need to calculate the speed, which is true for calculating gamma but not for calculating the momentum.

Ch. 1 prob. P65 (p. 42 and A-1): Answer is 35.4.

Ch. 2 pp. 58-59: In Time Step 1, m. In Time Step 2 the calculation of the future position should read as follows:

Ch. 2 prob. P21 (p. 83 and A-1): Answers are

Ch. 2 prob. P41 (p. 86 and A-1): Answer is 13 cm.

Ch. 3 prob. P13d (p. 124 and A-1): Answer is N.

Ch. 3 prob. P27b (p. 124 and A-1): Answer to part(b) is .

Ch. 3 prob. P37e (p.125 and A-1): Answer to part (e) is N.

Ch. 3 answer to checkpoint 8 (p. 129): Units are m/s.

Ch. 4 answer to checkpoint 7 (p. 172): Part (a) is N.

Ch. 4 prob. P30 (p. 166): The answer is 30 N/m.

Ch. 4 prob. P33a (p. A-1): The answer to part (a) is .

Ch. 4 prob. P44 (p. 167): The answers are: (a) 44 N; (b) 29 N; (c) 74 N.

Ch. 5 prob. P14 (p. 208): The coefficient of friction between the floor and the bottom block should be 0.5.

Ch. 5 prob. P24b (p. 208): should be .

Ch. 5 prob. P33e (p. 209, p. A-2 ): The answer to part (e) is .

Ch. 5 prob. P37a (p. 210 and A-2): Answer to part (a) is 871 kg m/s/s.

Ch. 5 prob. P39 (p. 210 and A-2): Answer is kg.

Ch. 5 checkpoint 4 answers (p. 214): For points A and D, the answers to part (b) are nonzero, and the answers to part (c) are zero.

Ch. 6 Figure 6.42 (p. 252): The labels “1” and “2” should be interchanged.

Ch. 6 checkpoint 4 answers (p. 283): (a) negative, decreases, (b) positive, increases, (c) negative, decreases, (d) positive, increases, (e) zero, stays the same

Ch. 6 prob. P29 (p. 277 and A-2): Answer is 66 J.

Ch. 7 summary (p. 316): The first sentence at the top right of the page should say, “Sliding friction force can be modeled in terms of the ball-and-spring model of solids.” (A more detailed treatment of friction is found in Ch. 9.)

Ch. 9 prob Q7: The center of mass velocity is constant, thus the sketch should illustrate constant velocity like this one.

Ch. 9 prob. P43, Figure 9.63: The figure may be hard to understand. Here is an improved figure:

Ch. 11 p. 421, line 7: “The vector dot product” should be “The vector cross product”.

Ch. 13 p. 521, example entitled “Source Location”: The absolute value of must be used:

Ch.13 prob. P45c (p. 542): The answer to part (c) is ,

Ch. 13prob. P62 (p. 544): The electric field units should be N/C.

Ch. 13 answer to checkpoint 8 (p. 545): The second answer is missing, C, which is 2e.

Ch 14 EXP6 part g (p. 575): The field is

Ch. 15 p. 605, Step 4: In both cases the denominator should be inverted. The fractions should be written , which yields

Ch. 16, top of p. 641: The expression for is missing an overall minus sign.

Ch. 16, top of p. 653, 4th and 6th lines: pos=(…) should be pos=vector(…).

Ch. 16 Summary (p. 661): Field is *negative* gradient of potential; the correct field components should have minus signs:

Ch. 17 p. 689: In the VPython code fragment, just after the statement **while t** **tmax:** insert the statement **rate(30)** .

Ch. 17 p. 690: In the VPython code fragment, delete the statement **rate(1000)**, which is not needed, since no display is made in this loop.

Ch. 17 prob. P23b (p. 209 and A-4): Answer to part b for magnetic field is 0.166 J.

Ch. 18 by Figure 18.48 (p. 736): In the 2nd full paragraph, the electrons pile up at location 4. In the 3rd full paragraph, + charge accumulates at location 3.

Ch. 20 p. 819, Fig. 20.25: The caption should say “out of the page.”

Ch. 20 p. 820, Fig. 20.26: The caption should say “with an upward Coulomb electric field.”

Ch. 20 p. 822, Fig. 20.31: The magnetic field should point out of the page, as in the previous diagrams.

Ch. 20 prob. P72 (p. 863): The magnet is a cylinder with diameter 1 cm and length 3 cm.

Ch. 21 prob. P23 (p. 900 and A-5): Answer for direction is “into the page.”

Ch. 22 problems P40, P41, P42 (p. 938): These problems are associated with Section 22.7, not 22.6.

### Errata for previous editions

Second edition volume 1 (2007)