Chapter 3: Answers to Stop to Think Questions and Odd-Numbered Exercises and Problems

Stop to Think Questions

  1. 1. c. The graphical construction of A⃗1+A⃗2+A⃗3 is shown in the figure.

    The figure illustrates the parallelogram vector addition.
  2. 2. b. The graphical construction of 2 A⃗−B⃗ is shown in the figure.

    The figure illustrates the tip to tail method of addition of two vectors.
  3. 3. Cx=−4 cm, Cy=2 cm

  4. 4. c. Vector C⃗ points to the left and down, so both Cx and Cy are negative. Cx is in the numerator because it is the side opposite ϕ.

Exercises and Problems

  1. 1.

  2. 3.

    1. E sin θ, −E cos θ

    2. E cos ϕ, −E sin ϕ

  3. 5. 8 m

  4. 7.

    1. 3.8 m/s, 6.5 m/s

    2. 1.3 m/s2, 0.80m/s2

    3. −30 N, 40 N

  5. 9. 100 m, west

  6. 11.

    1. 5.7, 45°

    2. 2.2 cm, 27°

    3. 100 m/s, 84°

    4. 22 m/s2, 27°

  7. 13.

  8. 15.

  9. 17.

    1. 2.8

    2. 4.1

    3. 6.1

  10. 19. −0.071î+4.6ĵ

  11. 21. Bx=−2.5 m, By=4.3 m; Bx=0.0 m, By=5.0 m

  12. 23.

    1. 0 m, 26, 160 m

    2. v ⃗(t)=(10î+8.0ĵ)t m/s

    3. 0 m/s, 26 m/s, 6 m/s

  13. 25. C⃗=0.8î−4.5ĵ

  14. 27. B⃗=12î+12ĵ

  15. 29.

    1. 100 m lower

    2. 5.0 km

  16. 31. 90 m, 46° south of west

  17. 33. 31°

  18. 35.

    1. 34°

    2. 1.7 m/s

  19. 37.

    1. −3.4 m/s

    2. −9.4 m/s

  20. 39. Tx=450 N, Ty=310 N

  21. 41. 25° west of north, 385 paces

  22. 43. 4.4 units at 83° below the negative x-axis

  23. 45.

    1. (2.9 N)ĵ

    2. (−1.6 N)î