P16_026.PDF

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Chapter 16 - 16.26
26. (a) The textbook notes (in the discussion immediately after Eq. 16-7) that the acceleration amplitude
is a m = ω 2 x m ,where ω is the angular frequency ( ω =2 πf since there are 2 π radians in one cycle).
Therefore, in this circumstance, we obtain
a m =(2 π (1000Hz)) 2 (0 . 00040m) =1 . 6
×
10 4 m / s 2 .
(b) Similarly, in the discussion after Eq. 16-6, we find v m = ωx m so that
v m =(2 π (1000Hz))(0 . 00040m) =2 . 5m / s .
(c) From Eq. 16-8, we have (in absolute value)
|
a
|
=(2 π (1000Hz)) 2 (0 . 00020m) =7 . 9
×
10 3 m / s 2 .
16-4, but here we will use trigonometric
relations along with Eq. 16-3 and Eq. 16-6. Thus, allowing for both roots stemming from the
square root,
§
sin( ωt + φ )=
±
1
cos 2 ( ωt + φ )
v
ωx m
=
±
1
x 2
x 2 m
.
Taking absolute values and simplifying, we obtain
|
v
|
=2 πf x 2 m
x 2 =2 π (1000) 0 . 00040 2
0 . 00020 2 =2 . 2m / s .
(d) This can be approached with the energy methods of
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