CT 1.2.2
If I whack a ruler hanging off the
desk, I can make a “note”.
What happens if I move it back so
less hangs off the edge, but I
whack it just as hard?
A) Pitch , loudness similar
B) Pitch similar, loudness
C) Pitch , loudness
D) Pitch , loudness similar
CT 1.2.3
What determines pitch?
Which is the most important feature
of the instrument/source of
sound?
A) Length/size
B) “Bendability”/rigidity
C) Heaviness/density of material
D) Amplitude (how hard it is struck)
E) More than one of the above
E) Something else
WHY?
CT 1.3.1
CT1.2.4
Let’s fill the Tibetan singing bowl with
water. What happens to the pitch of
the tone it makes?
A)
B)
C)
D)
goes up
goes down
pretty much unchanged
no way to know this without
trying
The picture shows “displacement as a function
of location along a string”
What is the wavelength (“λ”)?
a
d
b
x
c
e) None of these
Why?
What is the amplitude?
1
CT 1.3.2x
speaker
dust
A dust particle is located in front of a
speaker. The speaker moves back and forth at
a constant rate, creating a loud sound wave.
Which choice below shows the motion of the
dust particle?
A)
(up and down)
B)
(pushed steadily to the right)
C)
(left and right)
D)
E)
CT 1.3.3x
I grab the left end of a LONG string and
wiggle it up and down. There is a purple
painted spot somewhere on the string.
What choice below best shows the motion
of the purple spot?
A)
(up and down)
B)
(pushed steadily to the right)
C)
(left and right)
D)
(no motion)
(circular path)
E)
(no motion)
(circular path)
CT 1.4.1
CT 1.3.4x
Transverse and longitudinal
• Which one of the following is
most likely to be impossible?
A:
B:
C:
D:
E:
Transverse waves in a gas
Longitudinal waves in a gas
Transverse waves in a solid
Longitudinal waves in a solid
They all seem perfectly possible
Approximately how close is a thunderstorm
if you see lightning flash and hear a clash
of thunder after counting up to 6 seconds?
(the speed of sound is 344 m/s)
a) 0 km
b) 1 km
c) 2 km
d) 6 km
e) None of these
2
CT 1.4.3
CT 1.4.2
You are traveling on a commercial airplane (say
a Boeing 757). Relative to the speed of sound
you are traveling:
a)
b)
c)
d)
e)
much slower than sound
a little slower than sound
the same speed than sound
a little faster sound
much faster sound
Sound travels at a speed of 344 m/s (770 mph).
How fast does the air flow out of my mouth as I
speak?
a)
b)
c)
CT 1.4.4
In which of the following venues can you notice
a difference between the music you perceive
and the movements of the musicians (i.e. can
you tell that the sound has traveled a distance?)
a)
b)
c)
d)
The rear of the Fox Theater
Pepsi Center
Red Rocks amphitheater
All of the above
Much slower than 344 m/s
344 m/s
Much faster than 344 m/s
CT 1.4.7
Speed of sound
Which sounds travel the fastest through air?
a)
b)
c)
d)
e)
Higher pitch
Lower pitch
Louder sounds
Quieter sounds
They all travel at the same speed
3
CT 1.4.6
CT 1.4.5
In a 32 o C room sound travels…
a) > 344 m/s
b) 344 m/s
c) < 344 m/s
When sound travels from a source to a listener,
what do air molecules never do?
a)
b)
c)
d)
e)
Travel from the source to the listener at
344 m/s
Move back and forth with the frequency of
the sound wave
Bump into other air molecules
Move in the direction of wave propagation
Air molecules do all of the above
What if the room is 32o F? Does the sound
travel faster or slower than a 32o C room?
a) Faster
b) Slower
c) Same speed
CT 1.5.1
105
If there is really a force of
N (that’s
100,000 N!) on each square meter of a glass
window, why is it that the window does not
shatter?
a)
b)
c)
d)
e)
That is such a small force it does not
matter
The total force exerted on the window is
not equal to zero
Glass is stronger than you think
There is an equal but opposite force
pushing against the window from the other
side
Gravity counteracts the force
CT 1.5.2
I stand on a scale with both feet and measure
My weight. If I stand on one foot, does the
reading:
a)
b)
c)
Increase
Decrease
Remain the same
I weigh 500 N, what is the force on each foot?
a)
b)
c)
500 N each
250 N each
It depends on the area of my foot
4
CT 1.5.2
CT 1.5.2
What is the area of my feet in m2 (Hint: my feet
are very roughly 25 cm x 8 cm)?
a)
b)
c)
d)
e)
200
20
2
.2
.02
What is the approximate pressure on each
foot?
a)
b)
c)
d)
e)
.125 N/m2
125 N/m2
1250 N/m2
1.25x105 N/m2
Not enough information
Convert this to atmospheres
a)
b)
c)
d)
e)
CT 1.5.3
I stand on both feet, when I lift one foot up the
pressure on the other foot (the one that
remains
on the ground)…
CT 1.5.4
Who is more likely to damage a hardwood
dance floor?
a)
b)
a)
b)
c)
Increases
Decreases
Remains the same
1.25x10-5 atm
1.25x10-3 atm
1.25 atm
125 atm
1.24x105 atm
c)
d)
A 250 lb cowboy wearing boots with 6 cm
x 6 cm heels
A 100 lb waif-like woman wearing 1 cm x 1
cm high heels
They will do equal damage
Not enough information to make an
informed choice
5
CT 1.5.5
CT1.3.xx
When the air is sucked out of this barrel, what
is going to happen to the barrel?
a)
b)
c)
d)
e)
The barrel will explode
The barrel will completely collapse
The barrel will collapse halfway
Absolutely nothing, it’s a reinforced steel
barrel!
I have no idea
If a big collision occurs in deep,
empty outer space (two asteroids
slam into one another, surrounded
by “vacuum”),
Does it make a sound?
A) Sure
B) Sure (if there’s an astronaut there
to hear it)
C) No.
6