PH 404 Acoustics Winter 2015-2016 M.
J. Moloney
Homework Assignments
Problem Set 1. Due Friday December 4, 2015
- Text 1.1
- Text 1.3
- Text 1.4
- Text 1.5
- Text 1.7
Problem Set 2 Due Tuesday December 8, 2015
- Text 1.11
- Text 1.12
- Text 1.13
- Text 1.23
- Text 1.25 a), b) d)
Problem Set 3 Due Monday December 14
(1st
Exam is Thursday December 17, 2015)
- Text 2.1
- Text 2.6
- Text 2.12 (a job for Maple)
- Text 2.17
Problem Set 4 Due Friday January 8,
2016
- Text Prob 3.1
- Text Prob 3.3
- Convert the strpulse.mws file (emailed) to one where the pulse
reflects from the boundaries by flipping over at the LH end (x = 0) but
not at the RH end.(x = L). It would also be OK to have the pulse remain
upright at each end, not flipping over at all.
Problem Set 5 Due Friday January 15,
2016
- A circular membrane has a radius of 0.10 m and a lowest resonant
frequency of 49.7 Hz, like example 3.3 p.87. Find the membrane mode for
a frequency of 145 Hz, and sketch the nodal lines, as done on p. 88.
Find the membrane mode for an angular frequency of 1093 rad/s and
plot the
nodal lines. (Handout, pp 5, 6, 7)
- A rectangular membrane has length Ly = 0.40 m and width Lx = 0.20
m.
Its
lowest resonant frequency is 126 Hz. This membrane is given a sharp
blow
so that a small region between x = 0.08 m and 0.10m and between y =
0.18
m and 0.22 m is given a velocity v =0.38 m/s while the rest of the
membrane
is at rest. Modify the maple worksheet I sent you so you get the
correct animation in time. This requires an analysis like was done in
Section 2.5, pp.
47-49.
You will have to carry out integrals in Maple over both x and y. Some
of what I sent you is intact, some you must restore.
- Text problem 4.1
- Text problem 4.5
Problem Set 6 Due Friday January 22,
2016
- Work out the odd-symmetry solutions for the flexural vibrations
of a
rod
or bar free at both ends
- Write down the odd-symmetry wave functions
- Express the y'' = 0 boundary condition at +/- L/2, and that for
y''' = 0.
- From these two (y'' = 0, y''' = 0) write down the equation in
kL/2 implied by satisfying free-end
boundary
conditions
- Find the lowest two odd-symmetry frequencies for a 12.7-mm
diameter aluminum bar 0.8 m long.
- Text 5.3
- Text 5.5
- Text 5.9
Problem Set 7 Due Friday January 29,
2014
- Text Prob 7.1
- Text Prob 7.7
- Text Prob 7.9
- A
helmholtz resonator has volume of 0.0230 m3, and a neck area
of 0.0025
m2. Determine its neck length L if its resonant frequency is
140.0
Hz.