Thread: Can anyone give me a nice science fair idea related to sound waves?

Hey guys, AbhiKap here

So we recently started Physics in my school - I am in 8th grade

We have a project due in a few weeks and it has to be about Physics

As I mentioned, we just started Physics so pls don't give any super complicated project ideas

It doesn't have to be about sound or TV waves but preferably - please make it relatively simple

The project must have a demonstration technique - anyway of demonstrating the project. Therefore, it cannot be something like radio TV antennas since I cannot possible bring a satellite dish in school to demonstrate.

Thanks,
AbhiKap55

We're not going to choose one for you, but I'd be glad to give my input as to any ideas YOU come up with.

My first thought went to a dog whistle. I don't know what you could demonstrate with it, but I never took physics. I am sure if you want to you, you can find something to demonstrate with a dog whistle.

I've always been fascinated by acoustic sound waves traveling through and affecting bodies of matter (such as fluids). Perhaps you can entertain something similar.

You can read up a little on what modern day technologies that employ sound waves; such as submarine sonar systems, speakers next to an empty tank of colored water/sand/etc, whales and dolphin long distance communications, the human auditory canal, etc. The list can be endless if you put your mind to it. You can spend an hour or two discussing with your team members about everyday devices that employ sound waves. Even the simple mobile phone microphone/speaker or headphones might be an interesting choice to start with. These few suggestions shouldn't pose too much difficulty for eighth grade science research projects.

Do drop by again when you and your team have made a decision. It would be interesting to know what the young are up to these days with science projects.

The Boy Who Sees Without Eyes | Watch Free Documentary Online

The link above is to a documentary about a kid who lost his eyes when he was three to cancer. They had to remove his eyes entirely. He eventually learned to "see" with echo location. He would click with his mouth and be able to detect his surroundings well enough that he didn't use a cane and could ride a bike and skateboard in the street without hitting parked cars.

Originally Posted by scoobydoo1

I've always been fascinated by acoustic sound waves traveling through and affecting bodies of matter (such as fluids). Perhaps you can entertain something similar.

I too have always appreciated processes that allow us to 'see' invisible forces - even down to the most basic "Iron filings and a magnet".

There are some bizarre things you can do with sound and non-Newtonian fluids - but I think they are probably too 'obvious'.
But something like that is definitely the kind of direction I would head in.

I think cornstarch and water over a speaker is a good experiment for someone in 8th grade.

Originally Posted by RedPanda

There are some bizarre things you can do with sound and non-Newtonian fluids - but I think they are probably too 'obvious'.
But something like that is definitely the kind of direction I would head in.

Originally Posted by Flick Montana

I think cornstarch and water over a speaker is a good experiment for someone in 8th grade.

There are some interesting online videos on this to be found, and they might be a good place to start if AbhiKap55 do decides to go in that direction. Perhaps to toss things up a little, food coloring may be added into two (or more) separate cornstarch mix to see if there's anything interesting happens there (i.e. if different colored portions will combine together, or stay separate). A low tech and possibly (dollar) affordable set of computer speakers, cornstarch, water, food coloring, and a piece of plastic wrapper is possibly all it takes to get it done.

I do advise not simply going about it in the standard way, as school science teachers love when students go creative with the presentation of their science projects. Food for thought.

Hey guys, AbhiKap55 here

Thank you for all your responses - I really appreciate them

I decided to research Why the Sky is Blue and my teacher said this is a great choice

I just have one request: I have thought and though but cannot find a way to demonstrate this in class

I thought about taking a reflective paper and maybe using that - but I cannot find a way to use it

Does anyone have any ideas pls?

Thanks,
AbhiKap55

Originally Posted by AbhiKap55

Hey guys, AbhiKap55 here

Thank you for all your responses - I really appreciate them

I decided to research Why the Sky is Blue and my teacher said this is a great choice

I just have one request: I have thought and though but cannot find a way to demonstrate this in class

I thought about taking a reflective paper and maybe using that - but I cannot find a way to use it

Does anyone have any ideas pls?

Thanks,
AbhiKap55

I would think you would need a prism and demonstrate how the sunlight shines through the atmospheres at different angles depending on the time of day and how much humidity is present. because at sunset the sky is not blue. different angles would cause the light to be bent or broken into different wavelengths. Like I said though, I never took physics. you would need to do your own research and then get creative.

Hi there best of luck with your project.

Why is the sky blue?

Originally Posted by Ascended

Hi there best of luck with your project.

Why is the sky blue?

Thanks for posting that. This was very helpful. Just to clarify, according to the site you linked, if I get a graduated cylinder about 75% filled with water and add a teaspoon of milk, and shine a torch through it in a room, the color would be different depending on the angle? Seems interesting - will try that soon.

So, this is what it's like to have a curious, scientific mind.

We've all splashed around with soapy water and made bubbles. What I noticed recently is how the number of bubbles grows. It certainly doesn't grow by a so-called "arithmetic progression" ... that is, one splash, 10 bubbles, another splash, 20 bubbles, a third splash, 30 bubbles, etc. We all know that 's too slow a progression because after a few splashes, we go from a few bubbles to far too many to count easily. Maybe the number grows by a so-called "geometric progression" ... that is, one splash, 10 bubbles, another splash, 100 bubbles, a third splash, 1,000 bubbles, etc. Who knows? But that's what your project will discover!

You will want to perform this experiment several/many times.
You will want to perform it the same way every time.
The same amount of water at the same temperature,
The same amount of the same soapy stuff to make the bubbles,
The same bubble maker (something simple like a small egg whisk),
Dropped from the same height and at the same orientation,
(You may need to tie a string on its handle to pull it out because it might sink. (Don't pop any bubbles when pulling it out!)
Etc.

You might need to take photos of the bubbles in order to count the high numbers of them that will start appearing.

You'll check for repeatability among experiments (that is, do you get similar numbers in each experiment?). You may need to reject the results from a few/some experiments because they are outliers (that is, they don't conform to the progression from the other experiments). In your report, you can discuss why they are outliers.

Then, go to work on the numbers, and try to find how the number of bubbles progresses. You might/probably need some help here. You can use Excel to see which trendline fits best (it gives you six to choose from).

Once you find an equation, n_bubbles = f(n_splashes) that fits best, speculate about why it applies to bubble-making.

For problem encountered (and you will encounter problems), describe, if possible, what caused the problems and how you resolved them.

There's probably other parts of the project and report that your teacher requires.

This project is almost guaranteed to make a splash in your class.

Find the Eigen frequencies of puddles of water.

I was JUST thinking about that dancing water experiment. I'm not sure it's within the scope of an 8th grade project, but I'm pretty sure that if you committed to it, you would win all the awards.

Okay, here’s another project.

— NEWS ALERT —

On a quiet morning in New York City,
an airplane slammed into a skyscraper
and people feared that war had come to America.

Except that it happened Saturday 28 July 1945, and the plane slammed into the Empire State Building.

The pilot had flown out from an airfield near Boston and intended to land at the Newark Airport (now called Newark Liberty Intl Airport) in New Jersey. The ATC at Municipal Airport (now called LaGuardia Intl Airport) in Queens warned him about the heavy fog and insisted that he land at Municipal. The pilot insisted he could fly to Newark using landmarks, and he attempted to do so.

The pilot was unfamiliar with the plane he was flying and unfamiliar with the area he was flying over, but he had a general understanding of the area. He knew that he had to fly westward past the island of Manhattan to get to New Jersey, and he knew that Newark Airport was southwest of the island of Manhattan. It seems that he thought that he was northeast of Manhattan and that he thought that he saw the George Washington Bridge spanning the Hudson River below him. Actually, he was five miles south of the George Washington Bridge, and he actually saw the 59^th Street Bridge spanning the East River. As he prepared to land, he was really over Manhattan and he was approaching the Empire State Building — the world’s tallest building in 1945.

The pilot turned southwest toward what he thought would be Newark Airport, and he lowered his landing gear. He began to descend below the dense fog to look around and get his bearings. When the plane dropped below the fog, he found himself flying 500 feet over Fifth Avenue and dodging the towering skyscrapers around him. Smith had to struggle to maneuver the bomber and avoid the buildings.

At 9:49 AM, the ten-ton airplane crashed into the north side of the Empire State Building at the 79th floor about 900 feet above the ground.

In the offices of the North American Society of Civil Engineers, located on the 15th floor at 33 West 39th Street, the roar of the airplane’s engines caused someone speaking into a dictation machine to interrupt the dictation, but the machine continued to record. This recording can be found on the Internet on various sites. You should download it and try to clean it up for better sound quality (partly because you may want to play it as part of your project).

The job of the 8^th Grade Forensic Scientist to use the recording and other data to —

• Research the Internet and write up a more complete description of this tragedy,
• Produce a map of the general area, including the various landmarks, intended destination, and the ESB,
• Determine whether the airplane’s engines were malfunctioning or not (listen to the engine noises in the recording),
• Assume the airplane flew directly over the recorder,
• Determine Time Zero, when the airplane was over the recorder (this will be the middle of the Doppler Effect heard in the recording (also explain the Doppler Effect),
• Determine the time required for the sound of the crash to return from the ESB to the recorder (use speed-of-sound-in-air equations and try to find the air temperature for that day and at that time to make the speed-of-sound calculations more precise),
• Determine the time from Time Zero to the crash,
• Using measurements taken from a source such as Google Maps, determine the distance between the recorder's location and the north side of the Empire State Building (ESB), and using the time to the crash, calculate the average speed the airplane was traveling,
• Determine the type of airplane, and find its flight characteristics on the Internet,
• Determine how the calculated speed from the recording compares with its flight characteristics (that is, was it more than its safe maximum speed, or was it approximately at its cruising speed, or was it less than its landing speed, or etc).
• Determine the time required to fly from its altitude when it struck the ESB to pass over the top of the ESB by using the airplane’s Rate of Climb (from its flight characteristics).
• Determine the distance from the ESB required to be able to fly over it for the given Rate of Climb. Was this distance reasonable given the visibility for that day.
• Search the Internet for laws about how low one can fly over NYC in 1945, and determine whether the pilot violated that law.

(Also, put all this work given above in a reasonable order ... I was not typing them in perfect logical order.)

Make a summary of your findings and give your scientific assessment as to whether the crash was due to mechanical malfunction or pilot error. You may want to use percentages ... that is, say, 70% mechanical malfunction, 20% pilot error, and 10% uncertain/undeterminable. Briefly restate facts to support your findings. How do your findings agree or disagree with the official findings.

Note: You may be called to testify in front of Congress about your findings. (jk)