What We Did
The purpose of this project was to use our knowledge of waves and vibrations in order to create a variety of instruments. Our group made chimes for the chime instrument, a guitar for the string instrument, and a flute for the wind instrument. In order to understand how to create these instruments, we had to understand what waves were and how they worked.
Main Concepts
There are two types pf waves: Transverse waves and Longitudinal waves.
Transverse Waves: The electromagnetic spectrum (Which consists of visible light, microwaves, x-rays, gamma rays, infrared, and UV) are all transverse waves. Traverse waves vibrate perpendicular to their direction of travel. They also do not require a medium, so they can travel through a vacuum.
Longitudinal Waves: Sound waves are longitudinal waves. They vibrate in the same direction as their direction of travel. Longitudinal waves cannot travel through a medium, because they compress and expand the medium they travel through.
Both of these types of waves have the following properties
Wavelength: Wavelength is the distance from any point on one wave to the same point on the next wave. It can be calculated using the equation: wavelength =v/f
Frequency: Frequency is how many vibrations a wave has in a period of time. Frequency is measured in Hz, which is waves per second. It can be calculated using f=wave speed/wavelength, or f=1/period.
Wave Speed: Wave speed is the speed at which a wave travels.It is calculated by the formula wave speed=D/t, or
wave speed = f/wavelength. Wave speed is measured in m/s.
Period: Period is the amount of time between vibrations in a wave. It is measured in seconds. Period can be calculated using the equation: Period =1/f.
Amplitude: Amplitude is the distance from a wave's equilibrium to it's crest. It is the volume in sound waves. Amplitude is measured in meters and there is no formula because it is just a distance.
Transverse Waves: The electromagnetic spectrum (Which consists of visible light, microwaves, x-rays, gamma rays, infrared, and UV) are all transverse waves. Traverse waves vibrate perpendicular to their direction of travel. They also do not require a medium, so they can travel through a vacuum.
Longitudinal Waves: Sound waves are longitudinal waves. They vibrate in the same direction as their direction of travel. Longitudinal waves cannot travel through a medium, because they compress and expand the medium they travel through.
Both of these types of waves have the following properties
Wavelength: Wavelength is the distance from any point on one wave to the same point on the next wave. It can be calculated using the equation: wavelength =v/f
Frequency: Frequency is how many vibrations a wave has in a period of time. Frequency is measured in Hz, which is waves per second. It can be calculated using f=wave speed/wavelength, or f=1/period.
Wave Speed: Wave speed is the speed at which a wave travels.It is calculated by the formula wave speed=D/t, or
wave speed = f/wavelength. Wave speed is measured in m/s.
Period: Period is the amount of time between vibrations in a wave. It is measured in seconds. Period can be calculated using the equation: Period =1/f.
Amplitude: Amplitude is the distance from a wave's equilibrium to it's crest. It is the volume in sound waves. Amplitude is measured in meters and there is no formula because it is just a distance.
Our Instruments
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.
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.
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.
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.
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.
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.
Reflection
Overall, I thought this was a very successful project. I learned a lot about waves, and also about how instruments are made. For this project, we got to choose our groups, so I was with my friends. This made the project both fun and interesting. I felt that my group, Ashley, Hannah, Kelsea, and I did a great job balancing work and fun. We got all of our work done, but had a fun time doing it. Another thing we did well was collaboration. Since we all knew each other, we got along very well, and had no trouble working together. For example, we divided up the work very nicely, and that helped us finish the project on time. We were also all supportive of each other's ideas, and worked through any problems as a team. However, we did run into challenges, such as time management. For example, even though we did a decent amount of work every day, we still ended up going in at lunch a couple times to work on our instruments. One thing I struggled with personally was organization. During this project I focused mainly on the building aspect of things, and as a result, my note packet was much less organized than usual. Despite this project's challenges, however, it was very successful and effective.
Next Project: Electricity and Robotics. Previous Project: Outdoor Classroom