GO FIGURE!

The scientific method which involves--aksing questions, researching to synthsize available information, forming hypotheses, designing experiements, analyzing data, forming conclusions, asking questions...researching to synthsize available information, forming hypotheses, designing experiements, analyzing data, forming conclusions,...and so on and so on!

A "good" experiment includes:
1) a clearly stated, testable hypothesis

2) data collection that does not interfere with the subjects and is meaningful, unbiased and complete; it should use some standard form of measurement or a pre-determined scale

3) confounding factors are considered, variability is controlled for and possible sources of error reduced

4) consider data values--avoid the floor and the ceiling affects

5) adequate sample size

6) select an appropriate method of analysis for the data

7) no "massaging" of the data or results; results are analyzed in an unbiased fashion

8) repeatability, replication of the experiment

9) use a methodology and analysis tools that are as direct and simple as possible


A SOUND PROBLEM, REQUIRING SOUND THINKING
REFLECT ON YOUR SCIENCE KNOWLEDGE AND UNDERSTANDING OF SOUND...

Consider the following data on two related wind instruments...the flute and the piccolo.

Compare the two instruments. The piccolo is pictured above the flute.

Compare the two mouth pieces. The piccolo is pictured above the flute.

Compare the apertures (mouth piece openings) on the mouth pieces.

If we eliminate some confounding factors such as--the music being played is the same, the air being moved through the instrument is the same, the room temperature is the same, both instruments are "in tune," then how might the sound wave of the piccolo and flute compare, when playing the same piece of music or same note?

Would the wavelength, amplitude (pitch and intensity) vary. if so how?

How do you use the data in the chart and the pictures of the instruments to support your thinking?

THINK AND prepare a SOUND ANSWER, then........CLICK






















A SOUND ANSWER
(Response prepared by Mr. Don Pata, Grosse Pointe North Physics teacher :-)

In any wave - sound waves included - there are two measurements that can be easily made:

1) the frequency (how fast the wave is vibrating) and
2) the amplitude (the height of the wave).

In sound, these two factors are manifested as follows:

frequency --> pitch

amplitude --> volume or intensity

(I know you already know this but I need to state it anyway).

In any instrument, setting up a standing wave produces a sound - which in wind instruments are areas of alternating low and high air pressure.

The main factor that affects the pitch of the note played is the LENGTH of the tube. By changing the length of the tube, the length of the standing wave changes, causing a new wave with a different pitch. Generally speaking, the longer the tube the lower the note. Example: a trombone slide can be slid outward and change the length of the tube, making the tube longer and you know what that sounds like.

Shortening the length of the tube (going from a flute to a piccolo) will shorten the length of the standing wave and raise the pitch of the note being played, thus increasing the frequency of the sound wave.

The loudness of a note or the intensity is controlled by two factors -

1) the shape of the instrument and
2) the player.

Since the flute and piccolo have the same general shape, you could assume that the notes produced by the same player, blowing the same across the aperture would create a wave with the same intensity and the same amplitude of the wave.

The shape of the instrument does matter, in that the open bell shape of the end of a trumpet, for example, will produce a much louder sound - a wave with much bigger amplitude than a flute. Notes played by musical instruments are complex and there are many factors that affect the timbre of a note.

For actual graphs of the sound waves of the piccolo, flute, clarinet and tuning forks...click here!