Errata for G. Loy, Musimathics, Volume 1 (2007)

First see Gareth Loy's own Errata. This book is great for our course, except in its faulty coverage of basic kinematics and physics, for which an introductory college physics book such as Giancoli's should be consulted, or even Rossing, Moore and Wheeler. The following errors are present:
• p.14 last line: should read, `Real numbers include all integers, all possible fractional values, and all irrationals as well'. (Note the reals must include the irrationals: sqrt(2) is not a rational)
• p.22 Fig 2.10: penultimate note in F major scale is E not E#
• p.29, Fig 2.19: The plus signs in the list `f + 2f + 3f + ...' are mathematically meaningless. If multiples of a frequency f are superposed, the frequencies do not get added. Fig. 2.27 better represents partials.
• p.43, Fig. 3.1: As above, plus signs are mathematically wrong.
• p.104, (4.13) and preceding 2 eqns: The formula a_average = s/t^2 is wrong, and is missing a factor of 1/2 (although it is still misleading). This stems from a confusion between average v and Delta v (change in velocity). The paragraph surrounding (4.13) should be ignored, and (4.12) should read same as (4.14). This causes a bunch of quite serious trickle-down errors:
• p.111: 2nd and 3rd line of equations, should be entirely cut since it is wrong and a misleading derivation of kinetic energy. This style of derivation specifically would apply only to uniform acceleration which is not mentioned.
• p.111, (4.28) missing factor of 1/2
• p.143, 8th line down: E_k=mv^2 missing factor of 1/2
• p.144: (5.27) missing factor of 1/2
• p.132, (5.8): alpha should be defined as the limit of Delta omega / Delta t as Delta t goes to zero. The rest given is wrong. This is analogous to the discussion of linear acceleration.
• p.134, bottom, in bold: Should read, `Circular motion is the result of a centripetal force applied at right angles to the instantaneous velocity.'
• p.194: there is an error persisting throughout this page down to the final equation. If a speaker has intensity I, then at twice the distance the intensity is I/4, not sqrt(I). This mistake affects each equation on this page: sqrt should be replaced by a factor 1/4, and squaring by a factor of 4.
• p.231 3 lines from bottom: Statement that only relative velocity matters for 2D Doppler is wrong. Just as with 1D Doppler, both source and receiver absolute motion (ie relative to the air) matter.
• p.232: this whole page is incorrect and should be ignored; 2D Doppler is covered in other books. In brief, at position 3 there *is* relative velocity, just not along the line-of-sight. I believe Loy is using the symbol z_bar to mean line-of-sight velocity, in which case it is given by ux/z not the complicated expression given. This makes the main result (7.26) wrong.
• p.246: V = 7.5 * 10^4 or 7.5E4, but not 7.4^{-4}.
• p.460 Ch. 5 Note 4: Circular motion certainly is not the *vector sum* of centripetal force and linear velocity. These two quantities have different units so cannot be added! 