Physics Rocks! Paper

Physics Rocks!

For my Physics Rocks! Project, I decided to make a trumpet out of food. There are three parts, including mouthpiece, base, and bell. Holes in the top help to change the notes, but it is a brass instrument, in the sense that the player must buzz their lips like they are playing a brass instrument.

The first part of the trumpet is the mouthpiece. The mouthpiece is made of a vegetable that is dense throughout the middle (I couldn’t figure out what the vegetable actually was, but it’s carrot-ish). This makes the place where the player contacts their lips to the instrument more easily carved. I created the mouthpiece by cutting the vegetable at 5.0 cm. I then drilled a hole through it and carved the larger end on the inside to make the hole wider. The mouthpiece is important, because it helps the player create vibrations, or sound. Sound made by the mouthpiece is both crude and high because of the short length and narrow tube. Since the length of the mouthpiece is .05 m, and the speed of sound is 340 m/s in air, the frequency of this sound would be 3400 Hz. Because of the poor quality of sound, more parts are needed on the instrument.

The base of the trumpet is a cucumber. This part lowers the pitch of the instrument greatly, and makes a better, nicer sounding tone. The different sound is created by the greater length and radius of the tube, which creates a lower frequency when played. The length of the cucumber is 21.0 cm, so the frequency alone is 809.5 Hz. However, when connected to the mouthpiece, the length is not the two added together, or 26 cm. The mouthpiece is fitted into the cucumber, so the length of the two combined is 23.3 cm. The frequency of the two together is 729.6 Hz. Also, because of the variation of shape, the instrument’s harmonic series changes. The shape is changed because the hole is larger in the cucumber than the mouthpiece. I did this by using a larger sized drill bit when drilling the hole. To make the holes, I drilled into the cucumber from the side with an even smaller bit, and then cared around them to make it look good.

Finally, the bell of the trumpet is made out of half a pepper. This addition was added for visual appeal. It is seen, because its electromagnetic frequency is between 4.3x10¹⁴ and 7.5x10¹⁴. Also, since it is orange, it has a wavelength of around 590-620nm. There is no difference in the sound my trumpet makes because of this pepper, however, because it does not increase the length of the tube.

When the instrument is played, as it is closest to a brass instrument, more than one pitch can be made with the same fingering. This is because the 3400 Hz measurement is based on if the trumpet was producing a first harmonic sound. A second harmonic would make a higher frequency. In this case, second harmonic would be 6800 Hz. The third, fourth, and more harmonics can also be made; very many notes can be played.