Annex A-Group Research Proposal

Group Project Proposal (Science)


Names: Jane Ee(02), Rachelle Woo(06) and Zou YunChuan(25)

Class: S2-05

Group Reference: A / B / C / D / E / F / G / H  / J /  K  / L /  M  

  A.    Indicate the type of research that you are adopting:

[    ] Test a hypothesis: Hypothesis-driven research
e.g. Investigation of the anti-bacteria effect of chrysanthemum
[    ] Measure a value: Experimental research (I)
e.g. Determination of the mass of Jupiter using planetary photography

X ] Measure a function or relationship: Experimental research (II)
           Investigation of the effect of frequency on the formation of stationary nodes in a standing sound wave

[    ] Construct a model: Theoretical sciences and applied mathematics
e.g. Modeling of the cooling curve of naphthalene 

[    ] Observational and exploratory research
e.g. Investigation of the soil quality in School of Science and Technology, Singapore  

B. Type & Category:

Type of research: 3  (Write down one number from 1 to 6)

Category  –  19 (Write down one number from 7 to 20)

Sub-category –  g,k:acoustic  (Write down the sub-heading alphabet)

Application of project relevant to SST Community, Society or the World:

The concept of stationary waves is used in the Grand Organ and other musical instruments

The concept of stationary waves can also be used in research on easy to improve microwaves as microwaves uses stationary waves to heat food

C.    Write down your research title:

Investigation of the effect of frequency on the resonance effect of sound in an open pipe
D.   (a) Aim / question being addressed 

To find out which are the frequencies that resonance occurs at distance of sound source being 1m


1) What are sound waves?

2) If sound waves are pressure waves, can they be used to levitate objects?

3) What are the applications of standing waves and harmonics?

4) how to get standing waves?

5) what are pressure nodes?

6)what is the formula for the amount of waves in a closed pipe


1.Sound is all around us everyday but we probably don’t think of sound as a physical presence. We hear sounds, we don't touch them. the only exceptions may be in loud nightclubs, cars with window-rattling speakers and ultrasound machines that make you feel like your innards are being moved. But even then, you most likely don’t think of what you feel as sound itself, but as the vibrations that sound creates in other objects. The idea that something so simple can lift objects can seem unbelievable, but it's a real phenomenon. Acoustic levitation takes advantage of the properties of sound to allow solids, liquids and even heavy gases to float. (How stuff works, 2007)

2. In the past, scientists have used everything from laser beams to superconducting magnetic fields to levitate objects.The principle behind the acoustic levitation is simple: Sound waves, which are waves of high and low pressure that travel through a medium such as air, produce force."We've all experienced the force of sound — if you go to a rock concert, not only do you hear it, but you can sometimes feel your innards being moved," Drinkwater told Live Science. "It's a question of harnessing that force."By tightly orchestrating the release of these sound waves, it should be possible to create a region with low pressure that effectively counteracts gravity, trapping an object in midair. If the object tries to move left, right, up or down, higher-pressure zones around the object nudge it back into its low-pressure, quiet zone.But figuring out the exact pattern of sound waves to create this tractor force is difficult, scientists say; the mathematical equations governing its behavior can't be solved with a pen and paper.(Live Science, 2015)

what is a sound wave?
A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it get further away from the source of the sound. The source can be any object that causes a vibration, such as a ringing telephone, or a person's vocal chords. The vibration disturbs the particles in the surrounding medium; those particles disturb those next to them, and so on. The pattern of the disturbance creates outward movement in a wave pattern, like waves of seawater on the ocean. The wave carries the sound energy through the medium, usually in all directions and less intensely as it moves farther from the source.
The idea that sound moves in waves goes back (at least) to about 240 B.C. The Greek philosopher Chrysippus (c. 240 B.C.), the Roman architect and engineer Vitruvius (c. 25 B.C.), and the Roman philosopher Boethius (A.D. 480-524) each theorized that sound movement might take a wave form. (WhatIs,2005)

If sound waves are pressure waves, can they be used to levitate objects?
“Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.

Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave. If a detector, whether it is the human ear or a man-made instrument, were used to detect a sound wave, it would detect fluctuations in pressure as the sound wave impinges upon the detecting device. At one instant in time, the detector would detect a high pressure; this would correspond to the arrival of a compression at the detector site. At the next instant in time, the detector might detect normal pressure. And then finally a low pressure would be detected, corresponding to the arrival of a rarefaction at the detector site. The fluctuations in pressure as detected by the detector occur at periodic and regular time intervals. In fact, a plot of pressure versus time would appear as a sine curve. The peak points of the sine curve correspond to compressions; the low points correspond to rarefactions; and the "zero points" correspond to the pressure that the air would have if there were no disturbance moving through it. The diagram below depicts the correspondence between the longitudinal nature of a sound wave in air and the pressure-time fluctuations that it creates at a fixed detector location.”- (The Physics classroom, 1998)

3) What are the applications of standing waves and harmonics?

“Microwave ovens. The frequency of the microwaves in an oven, 2.45 GHz, was chosen to give moderate absorption by typical food. (Too little absorption wastes energy, too much just crisps the surface of things.) But the corresponding wavelength, 12.5 cm, is a bit of a nuisance, because if you pump microwaves of that wavelength into a metal box, you get standing waves of that size, which is pretty big compared to food. That means you need a turntable to make sure that the food doesn't linger in a hot spot and cook unevenly.” (Quora, 2014)

“In the context of music, how high or low a note is depends on the frequency of the sound wave.

In string instruments, a plucked or bowed string makes the note is does because only certain frequencies of stationary (or "standing") waves are able to form on that string under those conditions (e.g., a finger holding down the string at a certain position). Any vibrations that aren't at the right frequencies to make standing waves quickly cancel themselves out, and so it's the standing wave frequencies that we actually hear.

Similarly, for woodwind instruments, we get the notes we get because of what standing waves are able to form within the tube of air inside the instrument.

Strings and woodwinds sound different from one another because they allow different combinations of overtones (higher-frequency standing waves) to form.” (Quora, 2014)

how do you get standing waves?

“A standing wave pattern is a vibrational pattern created within a medium when the vibrational frequency of the source causes reflected waves from one end of the medium to interfere with incident waves from the source. This interference occurs in such a manner that specific points along the medium appear to be standing still. Because the observed wave pattern is characterized by points that appear to be standing still, the pattern is often called a standing wave pattern. Such patterns are only created within the medium at specific frequencies of vibration. These frequencies are known as harmonic frequencies, or merely harmonics. At any frequency other than a harmonic frequency, the interference of reflected and incident waves leads to a resulting disturbance of the medium that is irregular and non-repeating.”(The physics classroom, 1996)
what are pressure nodes?

4. “One characteristic of every standing wave pattern is that there are points along the medium that appear to be standing still. These points, sometimes described as points of no displacement, are referred to as nodes. There are other points along the medium that undergo vibrations between a large positive and large negative displacement. These are the points that undergo the maximum displacement during each vibrational cycle of the standing wave. In a sense, these points are the opposite of nodes, and so they are called antinodes. A standing wave pattern always consists of an alternating pattern of nodes and antinodes. The animation shown below depicts a rope vibrating with a standing wave pattern. The nodes and antinodes are labeled on the diagram. When a standing wave pattern is established in a medium, the nodes and the antinodes are always located at the same position along the medium; they are standing still. It is this characteristic that has earned the pattern the name standing wave.”(The physics classroom, 2000)

what is the formula for the amount of waves in a closed pipe


‘f’ is frequency where ‘v’ is the velocity of sound, ‘L’ being the length of the pipe and the number before the ‘L’ being the number of wavelengths produced  

(b) Independent variable

The frequency being imputed into the speakers







(c) Dependent variable

Decibel reading when independent variable frequencies are imputed

(d) Controlled variables/constant variables

(a)Speakers used
(b) The decibel meter used a
(c)Location where experiment is carried out(no wind)
(d)distance kept between the two speakers (1m)
(e)The placement of the tube and speakers(not to be moved throughout experiment)
(f)The distance of the decibel meter from the tube

      (e) Hypothesis

The sound will be louder at the frequencies of 165 hz, 330 hz, 495 hz,660 hz,825 hz and 990 hz

  E.    Method – Description in detail of method or procedures (The following are important and key items that should be included when formulating ANY AND ALL research plans.)

(a) Equipment list:
2x Speaker which frequency can be adjusted
1x Transparent Cylindrical tube(acrylic)
1x Pitch generator 
1x Amplifier
1x 2 meter of wires
1x decibel meter 
2x holder to keep tube from moving

(b) Diagram

Figure 1: Experimental setup used to find the frequencies where there is a new harmonic

(c) Procedures: Detail all procedures and experimental design to be used for data collection

1.  Set up the experiment as shown in the diagram above. make sure the wiring is correct

2. Adjust the frequency on the pitch generator to an audible frequency(20-20000 hz) to test if the speaker is working, if a sound is heard, move on to next step. 

If sound is not heard, check and/or change wiring and try again

3. Adjust the pitch generator starting from 60 hz then slowly turn it up towards 22000 hz

4. Check the decibel meter. when the db shown suddenly becomes high, note down the frequency shown on the tone generator

5. slowly increase the frequency up to 22000 hz and repeat step 4 where applicable 

6. repeat step 3 to 5 at least 2 times, average each test’s results, then transfer the information to the chart

(d) Risk, Assessment and Management: Identify any potential risks and safety precautions to be taken.

The experiment would involve electricity,there is a risk of electrocution if a student comes into contact with exposed wiring

Students must wear gloves made of non conductive materials when carrying out the experiment and all exposed wires must be wrapped around with insulating tape whenever possible.these measures are to prevent electricity from being passed to a student.
the end of wires involved in the experiment might be sharp, and if we are not careful, we might be barbed.

students must wear gloves mentioned in the previous risk, and unused wire’s ends must be tied in a knot in order to cover the sharp part
setting up of the experiment will involve soldering , hot metals will be produced , if in contact with bare skin, burns may occur

warn researchers about risk and make sure we do not  touch soldered parts for 5 min after soldering. make sure researches know of procedures of treatment in case of burns
As the experiments involve sound, and loud sound might damage eardrums of those around. The risk of hearing damage is present

make sure that experimentation does not go beyond 100 db or point , wear noise isolating ear plugs if possible and ensure that people that are not part of the experiment experiment not come too close to an ongoing experiment(3 meters)
Table 3: Risk Assessment and Management table

(e) Data Analysis: Describe the procedures you will use to analyze the data/results that answer research questions or hypotheses

1 .    Tabulate the data and calculate the average frequency needed to form another standing wave

      2 .    Plot a graph of the frequency and the frequency where a new standing wave appears  

      3 .    From the graph, we can find out how frequency affects the amount of standing waves produced

4 .   From the graph, we can find out at what frequencies new standing waves form

Frequency of the nth harmonics (Db)                             

test 1
test 2
test 3






Table 2: results table

Figure 2: Sample Graph of frequency (Hz) against intensity (Db)


F. Bibliography: List at least five (5) major sources (e.g. science journal articles, books, internet sites) from your literature review. If you plan to use vertebrate animals, one of these references must be an animal care reference. Choose the APA format and use it consistently to reference the literature used in the research plan. List your entries in alphabetical order for each type of source.

(a) Books

Angelica, C. C., & Hoyos, M. (2013). Manipulation of biomimetic objects in acoustic levitation. Paris, France:Universit´e Pierre et Marie Curie - Paris VI

(b) Journals

(c) Websites

Anson, E. (2014, september 26) What are some examples of stationary waves in real life? Retrieved from

Barton, M. ( 2104, september 5) What are some examples of stationary waves in real life? Retrieved from

Ghose, T. (2015, October 27 ) Real-Life 'Tractor Beam' Can Levitate Objects Using Sound Waves. Retrieved from

Henderson, T.(1998). Sound Waves and Music - Lesson 1 - The Nature of a Sound Wave. Retrieved from

Henderson. T (1996) Formation of standing waves. Retrieved from

Henderson.T (2000) What are nodes and anti-nodes. Retrieved from

Rouse, M. (2005, September). Definition sound wave. Retrieved from

Wilson, T. ( 2007, February 6). How Acoustic Levitation Works. Retrieved from

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