Physics 198
Homework 2
1. What is the difference between a longitudinal and a transverse wave? Give an example of
each.
Solution:
The difference is that in longitudinal waves the motion of the medium is parallel to the direction
of wave travel, while in t
Physics 198
Homework 3
Due September 3
1. A stone is dropped from the top of a cliff. It hits the ground below after 3.25 s. How high is
the cliff?
Solution:
Choose upward to be the positive direction, and take y = 0 at the bottom of the cliff. The initia
Physics 198
Homework 5
Due September 10
1. A force F = 100 N is applied to a box. The box is moved 2.0 m in the direction of the force.
a) Find work done by this force. b) Find work done by this force if the angle between the force
and the direction of th
Physics 198
Homework 1
Due August 27
This homework will not be collected and graded; solutions have been posted.
Diagnostic Math Quiz (Solutions)
Instructions: Simplify the following expressions. No calculators.
Physics 198
Homework 1
Due August 27
1) 10
Physics 198
Homework 7
Due September 15
Name
#_
(You must show your work or explain your answers to get full credit, simply writing a
numerical answer is not sufficient. You can type your solutions on this file, or write them on a
separate page, or you ca
Loudness level (phon)
An equal-loudness contour is a measure of sound pressure ( dB SPL), over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. Hearing sensitivity is maximum near the first
Definition:
Logarithms
a b = c b = log a c 10 b = c b = log10 c = log c
Properties:
3
log AB = log A + log B log A n = n log A
log( A / B ) = log A - log B
2.5
2
log 1 = 0 log 2 = 0.301 log 3 = 0.477 log 7 = 0.845 log 10 = 1 log 1000 = 3
log(x)
Numbers:
1
Hearing. (Perception of Sound)
We use four characteristics to describe how we perceive sound: pitch, loudness, tone quality (timbre), duration 1) The pitch of a sound is how "high" or "low" we perceive a sound to be (directly related to how we perceive fr
Reflection
a) Mirror reflection
normal to surface
1 = 2
1 2
in
S out source
S' image
1 2
wall (mirror) b) Diffuse reflection
c) Reflection from curved surfaces acoustical mirrors (curved mirrors) whispering galleries
Refraction: Snell's Law
1
2
In optics:
Real pipes
The pressure does not drop to zero right at the open end of a pipe. Because of this, the acoustic length is slightly grater then physical length.
For a cylindrical pipe of radius r the end correction (additional length) is 0.61r One open end:
L
Interference
Interference combination of waves (an interaction of two or more waves arriving at the same place) Important: principle of superposition
(r , t ) = 1 (r , t ) + 2 (r , t )
Valley
Peak (b) (a)
Valley
Waves source
(a)
No shift or shift by
(b)
9. Two-mass vibrator
Longitudinal vibration
m m m m
1 fa = 2
k m
1 fa = 2
3k m
Modes (a) and (b) are independent Transverse vibration
m
m
m m
Violin string normally vibrates transversely Two-mass vibrator has 2 longitudinal and 4 transverse modes of vibra
Oscillations
1. Different types of motion:
Uniform motion 1D motion with constant acceleration Projectile motion Circular motion Oscillations
2. Different types of oscillations:
Periodic oscillations A motion is called periodic when the system comes back
Dynamics
1. Newton's Three Laws
Newton's First Law
Existence of inertial systems of reference In inertial system of reference, any object acted by no net force remains at rest or continues its motion along straight line with constant velocity
Newton's Sec
6. Acceleration -Acceleration shows how fast velocity changes -Acceleration is the "velocity of velocity"
x v= t
x v = lim t 0 t
v a= t
v a = lim t 0 t
7. Motion with constant acceleration
at 2 x = x0 + v0 t + 2 v = v0 + at
Example: x 0 = 2m v 0 = 2m / s
Physics of Music
(PHYSICS 198)
Dr. Anatoli Frishman
frishman@iastate.edu
Web Page: http:/course.physastro.iastate.edu/phys198/
Introduction
Music and physics what is in common? What is physics? A science A basic science The most basic science Discovered b
1
Physics 198, Physics of Music Laboratory 9
Name _ Partner(s) _
This laboratory uses computer analysis of sound to investigate the spectra of real instruments and the human voice. If you didn't bring an instrument, please try one of the Physics and Astro
- -
1
Physics 198 PHYSICS OF MUSIC Lab 8: Real and Synthesized Sounds Name_ Partner(s)_ This laboratory uses computer analysis of sound to investigate the spectra of various instruments: real instruments, instruments sounds synthesized with a Casio keyboa
Physics 198
Homework 6
Due September 15
1. (a) If the kinetic energy of an arrow is doubled, by what factor has its speed increased? (b) If
its speed is doubled, by what factor does its kinetic energy increase?
Solution:
(a) Since
KE mv
1
2
2
, then
v
2 K
Physics 198
Homework 4
Due September 8
1. A 12.0-kg bucket is lowered vertically by a rope in which there is 163 N of tension at a given
instant. What is the acceleration of the bucket? Is it up or down?
Solution:
r
FT
r
mg
Choose up to be the positive di
Physics 198
Homework 7
Due September 17
1. (a) Calculate wavelengths in air for sound in the maximum range of human hearing, 20 Hz to
20,000 Hz. (b) What is the wavelength of a 10-MHz ultrasonic wave? Assume that speed of
sound is 343 m/s.
Solution:
(a)
2
Physics 101
Exam I
Fall 2015
1. Calculate: 5 4 =
A)
B)
C)
D)
E)
1
2
3
4
5
2. If two vectors are given such that
, what can you say about the magnitude and
A B 0
direction of vectors and ?
A
B
A)
B)
C)
D)
E)
Same magnitude, but can be in any direction
Sam
Physics 101
Exam I
Fall 2015
Name_
Physics 101
Fall 2015
Exam 1
Tuesday, September 29
Directions:
This 80-minute exam consists of 25 multiple-choice questions. This test is worth 25% of your
final grade.
The questions on this test are not in order of diff
Physics 198
Homework 20
Due November 17
1. Why are the bass strings of a piano wrapped with wire?
Solution:
The bass strings of a piano are wrapped to increase the mass of the string kipping small radius
and big tension. Bigger mass leads to lower frequen
Physics 198
Homework 21
Due November 19
1. What are the main cavities of the vocal tract? Which of these play a role in the production of
speech?
Solution:
They are the laryngeal cavity, the pharynx, and the nasal and oral cavities. All of them play a rol
Physics 198
Homework 19
Due November 12
1. How much does the fundamental bending mode frequency change when the length of a bar is
cut in half?
Solution:
The frequencies of a bar are equal to
f m vK / 8 L2 m 2
, so they are proportional to
1 / L2
. If the
Physics 198
Homework 17
Due November 5
1. What musical interval separates the open strings of a violin?
Solution:
The open strings of a violin are tuned to fifth.
2. Describe the spectrum of a string plucked at its center.
Solution:
If the string is pluck
Physics 198
Homework 14
Due October 20
1. How does the jnd for pitch generally compare to the critical bandwidth?
Solution:
Critical bandwidth is roughly equal to 30 difference jnds at the same frequency.
2. How does the pitch of a 200Hz tone depend on so
Physics 198
Homework 16
Due October 27
1. What is the main problem with the just scale?
Solution:
In the just scale, a few musical intervals are perfect but many other intervals are imperfect. For
example, if the fifths in the just scale are examined, fiv
Physics 198
Homework 18
Due November 10
1. What is popping frequency of a mouthpiece?
Solution: Popping frequency is the lowest resonance of a brass instrument mouthpiece.
2. Suppose that the length of trombone tubing is 275 cm in first (open) position. H