Chapter 8 Quiz -Science of Music

A flute plays one pitch despite the many frequencies which the player makes by blowing over its mouth hole because

sound of that frequency resonates as a standing wave

A trumpeter plays a desired pitch by adjusting the length of the pipe as well as producing

the appropriate harmonic

Even though a trumpet (like all brass instruments) has a closed end at the mouthpiece, it plays a full pattern of harmonics (including even harmonics). This is because

the bell raises lower frequencies so that they have a open-pipe pattern

An oboe has harmonics in the pattern of an open pipe. This is because

the inner bore of the instrument alters it harmonics' frequencies into that pattern

Consider a standing wave in an open pipe. At an end we find

the maximum motion of molecules

If a certain flute can play 250HZ as its lowest frequency, how low can a clarinet of the same length plays?

125Hz

A flute is 60 cm long (0.60 m). what is the lowest frequency this flute can play? (Assume it is at room temperature.)

283Hz

A certain closed pipe has a fundamental frequency of 150 Hz. What is the fundamental frequency of an open pipe of the same length?

300 Hz

The human ear canal (the narrow tube that lets sound into our heads) is 0.028 m long (just over an inch). The ear drum blocks the inside end, so it functions like a closed pipe. The air in this canal is at body temperature. What is the frequency at which this tube resonates (creates a standing wave). This is why our ears are most sensitive at this frequency. Use a calculator. (Hint: the speed of sound at 37oC -- body temperature -- is 353 m/s.)

3152 Hz

The difference in end conditions between clarinets and flutes and the kinds of standing waves that happen in each explains why

Clarinets can play lower pitches than flutes can play

If you blow over the opening of a water bottle, you can make a sound of a particular pitch. As you drink your water, and the water level goes down, the sound produced also changes. How?

The pitch gets lower

When playing a wind instrument, a higher air temperature will produce

a higher pitch because the speed of sound is increased

For standing waves in an air column, what do we find at a closed end?

a node

How could you describe a first harmonic standing wave in a closed pipe?

a node at one end, an antinode at the other

How could you describe a second harmonic standing wave in a closed pipe?

a node at one end, an antinode at the other, a node and an antinode inside

Keira Knightly recently showed how she can play her teeth. Watch the video. You can skip forward to about time 2:20. It lasts for less than a minute.

adjusting the size of the space inside her mouth to resonate at the right notes

For standing waves in an air column, what do we find at a open end?

an antinode

A second harmonic standing waves is produced in a certain pipe. We can be sure that this is

an open pipe

How could you describe a fundamental standing wave in an open pipe?

antinodes at each end, a node inside the pipe.

For sound in an air column in a pipe, reflections occur at

both open and closed ends

Without a bell, a trumpet would sound much

softer

Instruments like trumpets and trombones play different pitches in part because the musician can

change the actual length of the air column

The slide of a trombone serves to

change the length of the trombone's tubing.

The valves of a trumpet serve to

change the length of the trumpet's tubing

A trumpet being played is a(n) __________ pipe

closed

The sound produced when an air steam impacts a thin, flat obstacle is called a(n

edge tone

If you bring a cold trumpet indoors, and play it while it gradually warms up, you can expect the pitch to

get higher (go sharp)

If you bring a warm trumpet outdoors on a cold day, and play it while it gradually gets cold, you can expect the pitch to

get lower (go flat)

Even harmonics (harmonics 2, 4, 6, etc.) are missing from standing waves

in air columns in closed pipes

Covering the holes of a flute changes the pitch that is heard because

it changes the effective length of the air column

The bell gives the trumpet a higher volume because

it provides a more gradual change in impedance for sound waves leaving the trumpet

The frequency of a sound which forms a fundamental standing wave in a very long pipe will be

low

The frequency of the fundamental standing wave in a closed pipe is _______________ the fundamental frequency in an open pipe of the same length

lower than

The speed of sound is slower in carbon dioxide than it is in air at the same temperature. Therefore, the fundamental frequency for standing waves in a pipe filled with carbon dioxide will be ____________ that for a pipe filled with air.

lower than

Pulling the slide of a trombone out so that it has a longer pipe means that the pitch will be

lower.

For the fundamental standing wave in air in a closed pipe, what fraction of a wavelength fits into the length of the pipe? (Hint: think about what occurs at the two ends.)

one-quarter of a wavelength

The piano has different length strings for each note; a pianist does not change the length of the strings to play different notes like a guitarist or violinist does. A wind instrument that has a strategy similar to that of the piano is the

pipe organ