Chapter 1
18. 9.19 nm/s
Chapter 2
 6. (a) 5.00 m/s
    (b) 1.25 m/s
    (c) -2.50 m/s
    (d) -3.33 m/s
    (e) 0
14. 0.182 mi west of the flagpole
16. (a) graph
    (b) 41.0 m/s, 41.0 m/s, 41.0 m/s
        NOTE that the three values are the same only
        because all three selected intervals happen
        to be "small enough".  For an interval of 2.0 s
        (3.0 s to 5.0 s), you would get 41.75 m/s.
    (c) v_av = 17.0 m/s, much less than in (b)
22. (a) 0, 1.60 m/s², 0.80 m/s²
    (b) 0, 1.60 m/s², 0
34. (a) 5.51 km
    (b) 20.8 m/s, 41.6 m/s, 20.8 m/s; 38.7 m/s
Questions from Optional Reading 3
1. (a) 1.5 m/s²
   (b) 3 m/s
   (c) 12 m
   (d) 3 m/s
   (e) 3 m
2. (a) 20 m/s
   (b) 5 m/s²
3. 10 s
4. (a) 26 m/s
   (b) 60 m
Questions from Optional Reading 4
1. 10 m/s (the x velocity can never change)
2. 10 m/s E
3. 2 s  (v_y changes by -19.6 m/s²)
4. 4 s
5. 40 m
6. 19.6 m (the average v_y is 9.8 m/s for the UP trip)
Chapter 3
 6. (a) 6.12 units at 113° counterclockwise from +x-axis
    (b) 14.8 units at 22.5° counterclockwise from +x-axis
20. (a) 74.6° NofE
    (b) 470 km
30. (a) clears the bar by 0.85 m
    (b) falling; v_y = -13.4 m/s
36. 61.4 s
38. (a) 10.1 m/s at 8.53° EofN
    (b) 45.0 m
52. 14.0 m/s
Questions from Optional Reading 5
1. 31.4 rad/s
2. 62.8 m/s
3. 0.2 s
4. 94.2 rad
5. 188.4 m
Question from Optional Reading 6
The forces are:
F_BR, the force on the ball by the rope, UP
W_B, the weight of the ball, DOWN
The Third-Law partners of these forces are:
F_RB, the force on the rope by the ball, DOWN
F_G,EB, the force of gravity on the Earth by the ball,
        at the Earth's center pointing towards the ball
Chapter 4
 6. 7.41 min
 8. 312 N
26. a = 4.43 m/s², T = 53.7 N
40. (a) 55.2 degrees
    (b) 167 N
50. (a) 18.5 N
    (b) 25.8 N
56. 21.5 N
58. (a) 50.0 N
    (b) 0.500
    (c) 25.0 N
60. 0.814
64. (a) 9.8 N
    (b) 0.58 m/s²
68. 0.685 m/s²
Chapter 5
32. 5.11 m/s
38. friction has magnitude 4.23 N
    work by friction is -16.9 J
    work done by F is 47.9 J
42. (a) 2.29 m/s
    (b) 15.6 J
50. 2.92 m/s
66. (a) 582 trips
    (b) 90.5 W or 0.121 hp
70. (a) 306 J
    (b) -147 J
    (c) 0
    (d) 147 J
Chapter 6
 2. (a) 5.40 N⋅s toward the net
    (b) -27.0 J
14.  260 N directly away from the wall
20. (a) 0.490 m/s
    (b) 0.0201 m/s
22. thrower 2.48 m/s
    catcher 2.25 cm/s
24. (e) 2.22 m/s in the direction
        opposite to the velocity of B
28. 529 m/s
32. (a) 20.9 m/s East
    (b) 8689 J; both vehicles are warmer
        and both are deformed
38. (a) 2.50 m/s
    (b) 37500 J
44. 41.5 mi/h
72. (a) 1.07 m/s @ 29.7 degrees clockwise 
                         from the x axis
    (b) 31.8%
74. (a) 7.06 m/s
    (b) 2.54 m
Chapter 7
 2. 2.15 m, 123 m, 773 m
16. 2360 m/s²
26. 1380 N so he will not make it
28. (a) 24.9 kN
    (b) 12.1 m/s
36. (a) 5590 m/s
    (b) 3.98 h
    (c) 1470 N
42. (a) 3.77 m/s²
    (b) 3.26 s
50. (a) 0
    (b) 1290 N
    (c) 2060 N
52. (a) 2.06 m/s
    (b) 54 degrees
    (c) 4.70 m/s
Chapter 8
 8. 0.00669 nm, 0
36. (a) 5.35 m/s²
    (b) 42.8 m
    (c) 8.91 rad/s²
38. 30.3 rev/s
44. 35.6 rad/s
50. (a) 1.91 rad/s
    (b) initial  2.53 J
        final    6.44 J
52. (a) 3.58 rad/s
    (b) 539 J, which is the work done
               by the man during the
               walk inwards
56. 508 N (ignoring the mass of the door)
60. (a) 46.8 N 
    (b) 0.234 kg⋅m²
    (c) 40.0 rad/s
Chapter 9
 6. 22.1 N towards bottom of page in diagram
10. (a) 2.45 mm
    (b) 0.75 mm
12. 55.5 MPa; the arm should survive
18. (a) -0.0538 m³
    (b) 1090 kg/m³
    (c) for the enormous pressure change, the
        fractional change in volume is small (~5%)
20. (a) 65.1 N
    (b) 275 N
24. 2.31 lb (for interested students only)
25. The answer in the back of the book for this one
    is incorrect.  The online version, however,
    is correct.  The correct answer for the book's
    numbers is 26.6 N⋅m.
40. 154 in/s
48. (a) 15.1 MPa
    (b) 2.95 m/s
    (c) 4.34 kPa
64. 455 kPa
74. answers will be posted after this HW is due
82. 0.721 mm
Chapter 13
 6. (a) 327 N
    (b) 1250 N/m
 8. (a) 575 N/m
    (b) 46.0 J
24. 2.23 Hz
36. 58.8 s
42. (a) 0.20 Hz
    (b) 0.25 Hz
Chapter 14
10. (a) 0.05 fW
    (b) 0.05 mW
14. (a) 0.000132 W/m²
    (b) 81.2 dB
16. (a) 0.00796 W/m²
    (b) 109 dB
    (c) 2.82 m
18. answers will be posted after this HW is due
24. 41.2 kHz
26. (a) 0.0217 m/s
    (b) 2.000029 MHz
    (c) 2.000058 MHz
30. answers will be posted after this HW is due
32. answers will be posted after this HW is due
42. 9.00 kHz
50. 29.7 cm
60. 200 m/s
Question from Optional Reading 19
Point A, with Δpath = 0, would now be a point
of destructive interference, as would point C.
Point B, with Δpath = (1/2) a wavelength would
now be a point of constructive interference.
In the resulting standing wave, the positions
of nodes and antinodes would now be reversed.