Overview
For this project we started by learning about longitudinal and transverse waves. We learned that velocity= wavelength*frequency. We learned that sound waves are a form of longitudinal waves. As well, we learned different notes are based on different frequencies of sound waves. We then made a wind, chime, and string instrument that used what w had learned and played a 6 note scale.
Our Instruments
How They Work
Chimes
Our chimes work by vibrating at their natural frequencies; the longer chimes produce lower pitches, and the shorter chimes create a higher pitch. This is because the longer chimes vibrate slower, so they have a lower frequency and put out a lower pitch with the shorter chimes, it is the opposite. The shorter chimes vibrate faster, producing a higher frequency, and therefore a higher pitch. For our chime instrument, we decided to go with a unique design that suspends the chimes in the air using fishing wire. To start, we calculated the length we would need for each chime to produce a C scale. After we created the measurements, we cut the pipes. Next, we got two pieces of wood that would serve as the base of the instrument. Then we got 4 wood blocks and attached 1 to each corner. This provided our design with more stability, and gave us the idea to suspend the chimes in the air, rather than attached to the wooden base. Unlike other designs, the chimes are attached on both sides horizontally, instead of attached one 1 end, and dangling down vertically. Next, we drilled screws into the wooden base and strung fishing wire through our chimes and tied it to the screws on either end. This suspended the chimes in the air which provides a clear, unmuted sound. We also added a base support at the bottom of our instrument to insure stability and prevent the two sides from falling down. Our pipes were about 1mm thick, which affects the natural frequency of the object. The pipes we used create a louder and clearer sounds. The frequency of the vibrations is what creates the different notes on the chimes.
Note Length
C 14 in
D 13.199 in
E 12.52 in
F 12.12 in
G 11.43in
A 10.84 in
B 10.22 in
C9.89 in
Flute
A flute’s sound is based on the principle of vibrations. The flute works by forcing air to escape out of holes in the flute which are all set at different lengths. We control the output by plugging specific holes with our fingers. The holes that are closer in distance to the mouthpiece, make higher the sound of the pitch. By covering holes you force the air to travel a longer distance down the flute and too the end. For our design, we decided to go with a very simple design. The body of the instrument is made of PVC piping with half centimeter wide holes drilled in it. We also used a rubber stopper to push all the air out of 1 side. The vibrations occur when a person blows air over the mouthpiece which causes the air in the tube to vibrate.The pitches are higher when the holes are open closer to the mouthpiece because there is the zone of neutral pressure is closer to the mouthpiece caused by the influx of neutral pressure air brought in by the open holes, shortening the wavelength.
Note Distance from mouthpiece
A5...........5.1 in
G5...........6.2 in
F5...........7.4 in
E5...........8.1 in
C6...........8.8 in
B5...........10.1 in
Ukulele/guitar
Our guitar works by vibrating at half a wavelength of the natural frequency. Our building of this guitar was difficult. We decided that we wanted our instrument to play at the C4 scale. This means that it would have to be 66cm in length for the string. This is because the full wavelength for a C4 is about 132 cm. Since we want the guitar to play at half the wavelength, we made the length 66cm. The reason it vibrates at half of the wavelength is because of the wave going back and forth across the string creates one whole wavelength. This creates a natural frequency for each note. Another reason why our guitar works is because we use different tensions to create different notes. The next step of our guitar was to find the right note for each string. Although you can make each string a different length and you get a different note, you still have to tighten it to create the note. But for our guitar, we kept each string the same length and adjusted the string from there. A higher tension creates a higher note.For example, an A note is higher than a C note of the same octave. This is because the A note has a greater tension. The tension affects the note because it makes it so the string can’t vibrate as easily, which makes the string go faster. When it vibrates faster, it creates a higher note. To make our guitar louder we added a sound box. The sound box is a box on end of the guitar with a hole in the middle area. It is directly underneath the strings. When the strings produce sound, the sound box amplifies it. The reason it amplifies it is because the vibrations go into the sound box’s hole, then the vibrations reflect off the walls, and each wave will reflect on each other trying to get out of the sound box. This helps make the strings seem louder and give the guitar a powerful sound.
Note. Frequency (hz). Wavelength (cm)
C4........261.63..................131.87
D4........293.66..................117.48
E4.........329.63..................104.66
F4.........349.23. .................98.79
G4.........392.00..................88.01
A4.........440.00..................78.41
B4..........493.88..................69.85
Our chimes work by vibrating at their natural frequencies; the longer chimes produce lower pitches, and the shorter chimes create a higher pitch. This is because the longer chimes vibrate slower, so they have a lower frequency and put out a lower pitch with the shorter chimes, it is the opposite. The shorter chimes vibrate faster, producing a higher frequency, and therefore a higher pitch. For our chime instrument, we decided to go with a unique design that suspends the chimes in the air using fishing wire. To start, we calculated the length we would need for each chime to produce a C scale. After we created the measurements, we cut the pipes. Next, we got two pieces of wood that would serve as the base of the instrument. Then we got 4 wood blocks and attached 1 to each corner. This provided our design with more stability, and gave us the idea to suspend the chimes in the air, rather than attached to the wooden base. Unlike other designs, the chimes are attached on both sides horizontally, instead of attached one 1 end, and dangling down vertically. Next, we drilled screws into the wooden base and strung fishing wire through our chimes and tied it to the screws on either end. This suspended the chimes in the air which provides a clear, unmuted sound. We also added a base support at the bottom of our instrument to insure stability and prevent the two sides from falling down. Our pipes were about 1mm thick, which affects the natural frequency of the object. The pipes we used create a louder and clearer sounds. The frequency of the vibrations is what creates the different notes on the chimes.
Note Length
C 14 in
D 13.199 in
E 12.52 in
F 12.12 in
G 11.43in
A 10.84 in
B 10.22 in
C9.89 in
Flute
A flute’s sound is based on the principle of vibrations. The flute works by forcing air to escape out of holes in the flute which are all set at different lengths. We control the output by plugging specific holes with our fingers. The holes that are closer in distance to the mouthpiece, make higher the sound of the pitch. By covering holes you force the air to travel a longer distance down the flute and too the end. For our design, we decided to go with a very simple design. The body of the instrument is made of PVC piping with half centimeter wide holes drilled in it. We also used a rubber stopper to push all the air out of 1 side. The vibrations occur when a person blows air over the mouthpiece which causes the air in the tube to vibrate.The pitches are higher when the holes are open closer to the mouthpiece because there is the zone of neutral pressure is closer to the mouthpiece caused by the influx of neutral pressure air brought in by the open holes, shortening the wavelength.
Note Distance from mouthpiece
A5...........5.1 in
G5...........6.2 in
F5...........7.4 in
E5...........8.1 in
C6...........8.8 in
B5...........10.1 in
Ukulele/guitar
Our guitar works by vibrating at half a wavelength of the natural frequency. Our building of this guitar was difficult. We decided that we wanted our instrument to play at the C4 scale. This means that it would have to be 66cm in length for the string. This is because the full wavelength for a C4 is about 132 cm. Since we want the guitar to play at half the wavelength, we made the length 66cm. The reason it vibrates at half of the wavelength is because of the wave going back and forth across the string creates one whole wavelength. This creates a natural frequency for each note. Another reason why our guitar works is because we use different tensions to create different notes. The next step of our guitar was to find the right note for each string. Although you can make each string a different length and you get a different note, you still have to tighten it to create the note. But for our guitar, we kept each string the same length and adjusted the string from there. A higher tension creates a higher note.For example, an A note is higher than a C note of the same octave. This is because the A note has a greater tension. The tension affects the note because it makes it so the string can’t vibrate as easily, which makes the string go faster. When it vibrates faster, it creates a higher note. To make our guitar louder we added a sound box. The sound box is a box on end of the guitar with a hole in the middle area. It is directly underneath the strings. When the strings produce sound, the sound box amplifies it. The reason it amplifies it is because the vibrations go into the sound box’s hole, then the vibrations reflect off the walls, and each wave will reflect on each other trying to get out of the sound box. This helps make the strings seem louder and give the guitar a powerful sound.
Note. Frequency (hz). Wavelength (cm)
C4........261.63..................131.87
D4........293.66..................117.48
E4.........329.63..................104.66
F4.........349.23. .................98.79
G4.........392.00..................88.01
A4.........440.00..................78.41
B4..........493.88..................69.85
Concepts Used
Transverse Waves
Waves that move perpendicular to their path of travel. Can travel through a vacume since it doesn't need a medium. Ex: Electromagnetic spectrum (x-rays, gamma rays, light rays, micro waves, etc.)
Longitudinal Waves
Waves that travel by moving a medium along their path of travel. MUST have a medium so they can't travel through a vacume. Ex: sound waves
Wavelength
Frequency
Wave speed
Period
Amplitude
Waves that move perpendicular to their path of travel. Can travel through a vacume since it doesn't need a medium. Ex: Electromagnetic spectrum (x-rays, gamma rays, light rays, micro waves, etc.)
Longitudinal Waves
Waves that travel by moving a medium along their path of travel. MUST have a medium so they can't travel through a vacume. Ex: sound waves
Wavelength
Frequency
Wave speed
Period
Amplitude
Overview
this was a very short and sweet project. It went very smoothly. To start, we got all our work done in class so we didn't have to come in at lunch at all. Also, the work was split evenly and there were no communication problems. This probably had to do with the fact that we got to choose our own groups. This kept away problems and also, I think, helped us come up with more ideas since we were always talking. However, the talking cause some problems with staying on task. We weren't always the most focused. We also had a difficult time when building our guitar because we couldn't find proper string. One string was too thick, and one was too thin. We did finally find one inberween that worked, but the issue we faced was it ran out when we were half way done. We eventually fixed this and our guitar worked great!