Balloon powered car

[deleted-189284]

Hey
Im in grade 10 and I am doing this physics project named"balloon powered car". I am not doing it exactly the way thats given in the procedure part. I'm building the car,testing the distance it travels and making alterations in the size of wheels type of cardboard etc. most important thing is that i wil put steel weights on the car and see how far it goes then make a velocity vs time graph and tables. My tecaher said i can use a pressure meter too but i am not sure about where i will get that. My question is after making all these changes will this project be of my grade level?? If not what changes can I make..

Any help would be appreciated.
Thank you

[deleted-2131]

Hi Monadas,

What would you be using the pressure meter to measure? Perhaps I'm missing something, but I don't see how a pressure meter will help you measure velocity. As long as you analyze the physics of your vehicle in detail and methodically work through the engineering design process, I think you can make this balloon car project appropriate for a high-school level project.

Post back as you have other questions.

[deleted-189284]

Hi tdaly,
I don't know about the pressure meter myself. My science teacher told me to use that but I don't how. Leaving that, you said this project is of my grade level which means I have to explain in detail of the physics involved. Are you sure I have to use the engineering process not the scientific method? I don't need a hypothesis? I don't want to make any mistake with that.

Thank you

[deleted-2131]

Hi monadas,

A little more information about yourself will help me better help you. What grade, exactly, are you in, and what science, if any, science classes have you taken so far?

You are working on this project, correct?
https://www.sciencebuddies.org/science- ... #procedure

Because your teacher suggested using a pressure meter, it's a very, very good idea to talk to her or him and find out what your teacher envisioned you doing with the pressure meter. Ask your teacher is she or he can explain what they want you to measure with the pressure meter.

The balloon-powdered car project is best-suited to the engineering design process, rather than to the scientific method. (See the "Overview of the challenge" part of the procedure.) It's a good a idea to double check with your teacher that it's OK for you to do an engineering project with design criteria rather than a hypothesis, just to be safe.

Post back as you have other questions.

[deleted-189284]

Hi tdaly,
I am in 10th grade in a school in Guyana, South America. My teacher didn't know herself why she suggested me to use the pressure meter, so I am not using that anymore. And yes I am using engineering method and she said I don't need a hypothesis.
I just want a little help with my project. I am making two models, one with CDs as wheels and the second one with bottle caps as wheels. And i am testing both of them by putting weights and then i will make the distance vs time graph. I just want to know if all this ok? or is there anything i can add?
Lastly, i am struggling in figuring out the title of my project. I don't want to name it balloon powered car but something else. Any suggestions will be helpful.

[deleted-2131]

Hi Monadas,

This information is really helpful - thank you!

Because you are using the engineering design process, you will want to identify some specific design criteria. For example, because you are interested in the car's distance at various times, one of your design criteria might be that the car "travels (a certain distance) within (a certain time)". Then you can start with a prototype, such as a car with CD wheels, and test to see whether that car goes that specific distance within the allotted time. If the car doesn't, then you can make changes (one change at a time), such as adding weights, to see whether that change helps your car meet the design criteria. Keep careful notes about each change that you make; those notes will help you remember how your car's design evolved through the various tests that you do.

As far as a title goes, how about "Using balloons to go the distance"? I agree that picking the titles for projects can be tricky. I sometimes encounter the same challenge even now as I write papers!

It sounds like you are on a good track with your project. Post back as you have more questions - we are happy to help!

[deleted-189284]

Hi tdaly,
Thank you so much for your help with the title and project overall!!
So far, i dont think i will have any problems.
But i would be grateful if you can guide me with the background part of the project. I dont understand what i need to research for that part. I tried searching about balloon powered car but there is nothing on google. I want to know what exactly do i put for background for an engineering project.

Thank you

[deleted-2131]

Hi Monadas,

I'm happy to help

Here are a couple of pages that you might find helpful as you work on your background research. The first page describes how to figure out what you need to research. The second page provides some suggestions for finding the information that you need.

https://www.sciencebuddies.org/science- ... ml#keyinfo
https://www.sciencebuddies.org/science- ... nformation

Basically, you should focus on learning the science that you need to know in order to explain and interpret the outcome of your study. For your project, I suggest that you do some research on friction and air resistance because these are the two forces that will eventually cause your car to stop moving.

Because you are interested in a distance vs. time graph, it would also be helpful to learn about the kinematic equations. These equations will help you analyze the motion of the cars that you build. The equations describe the relationships between distance, time, velocity, and acceleration. Have you heard about the kinematic equations before in one of your classes? If you haven't heard of these equations and you would like to learn more about them, this is a great resource:

http://www.physicsclassroom.com/Physics ... Kinematics

I'm happy to help explain how these equations relate to your project, specifically, if this is a direction that you want to go in.

Post back as you have more questions!

[deleted-189284]

Hi tdaly,
Once again thank you for your help
Im really very thankful.
And yes i have learned kinematic equations before and i will use it !

[deleted-189284]

hi, tdaly
I would be glad to know your explanation for kinematic equations relating to my project.

[deleted-2131]

Hi Monadas,

I'm sorry that it's taken me so long to get back to you. I'm traveling right now, so my schedule has been a bit different from normal.

For your project, you know the initial position of the car and the initial velocity of the car. Because you are measuring the distance of the car at different times, you can calculate the car's velocity over each time interval.

velocity = (distance traveled in a time interval/time interval)

You can then compare the velocities of each car, in addition to the final distance traveled.

That's one example of how you can use kinematics to analyze your experiment. How do you plan on gathering the data for your distance vs. time graph?

[deleted-189284]

Hi tdaly,
My science fair presentation is next week Monday. I am still not done testing the two models of car I made: One with smaller wheels and one with bigger wheels. Are two models ok? So far I have the problem, background, materials, procedure, proposed solution, possible solutions and design. Do I need a research question (purpose) for engineering project? And do I include my proposed solution, which is a balloon car, in the list of possible solutions???


And my last query is how can this car be used in the future? How will it work if it has to work for real life? My teacher told me to look for" how does a hovercraft work". If you can please explain on this part then it would be great.

[deleted-2131]

Hi Monadas,

In my experience, it is a good idea to stop working on the project a few days early so that you have enough time to finalize your presentation. As a result, it's OK to stop with two two models that you already have and spend the next few days finishing up your analysis of the tests that you did do and putting finishing touches on your presentation.

I'm glad to hear that you have worked on your problem, background, materials, procedure, proposed solution, possible solution, and design. No, you do not need a research question (purpose) for an engineering project. Instead, you need to identify the problem you are trying to solve or the need you are trying to meet. The section might be better called a "test plan", if that section describes how you were testing the two cars. Yes, you should include your proposed solution (the balloon car) in the list of possible solutions. Then, you can explain why you chose to work on the balloon car solution instead of one of the other solutions you proposed.

With regards to how this car can be used in the future: you have a couple of options here. First, you could explain how other machines used stored energy to propel something. A rocket, for example, works on a very similar principle, although in that case the propellant is rocket fuel, instead of air. This website explains more about the similarities (and differences) between a balloon car and a rocket:

https://www.grc.nasa.gov/www/k-12/BGP/A ... _easy.html

Second, you could explain how the engineering design process is useful in real life. For this option, you could explain how engineers use test plans, design criteria, an iteration to invent and improve new products.

Post back as you have other questions!

[deleted-189284]

Hi, tdaly,
Thank you very much for the information.


So for each model I have a table like this:
Time trial 1 Time trial 2 Average time Distance (m) Speed
1
2
3
4
And i have the data for this too. Now I don't really understand that how a distance vs time or velocity vs time graph will show which car model is better. Please help me
And I will do the test with pennies so for that do i need to decide on a specific amount of pennies that the final model should carry before I do the testing??
Or is there any other test i can possibly do

Thank you

[deleted-189284]

Those 1m ,2m ,3m ,4m are for distance
I didnt put the actual data table just a outline

[deleted-2131]

Hi Monadas,

The first thing to do is to make the graph. Then, look at the graph and see what patterns you notice. For example, does one car model go farther than another? Or faster than another? If so, which car goes farther (or faster)? If the graphs for both cars look similar, that's OK, too.

Remember that with an engineering design project, you need to specify design criteria (e.g., the car will go X meters in X amount of time while carrying X pennies). Alternatively, you could test how the number of pennies on a car affects how far and fast the car travels. Either option is OK. in the first option, you would need to adjust the design of your car until the data demonstrate that the car meets the design criteria. With the second option, you would make a distance vs. time graph for each car with a different number of pennies. For example, if you tested cars with 0 pennies 1 penny, 2 pennies, 4 pennies, and 8 pennies, you would have a total of ten distance vs. time graphs (car #1 with 0 pennies, car #1 with 1 penny, car #1 with 2 pennies, car #1 with 4 pennies, car #1 with 8 pennies, car #2 with 0 pennies, car #2 with 1 penny, car #2 with 2 pennies, car #2 with 4 pennies, and car #2 with 8 pennies). Choose whichever option you like best.

Now, if you already have distance vs. time data for your cars (and it sounds like you do), then I wouldn't worry about doing the things I described in the previous paragraph. But, I would analyze the distance vs. time graphs that you already have using the questions that I suggested in the first paragraph.

Post back as you have other questions!

[deleted-189284]

Hi, tdaly
I am using it the first way you said- "(e.g., the car will go X meters in X amount of time while carrying X pennies)."
So between my two car models: one with cardboard wheels weighing 4.6 g each and one with sprite bottle caps wheels that weigh 2.6 g each, the car with bottle caps wheels is going the farthest with the 19.85 g of pennies. (the diameter of cardboard wheel is bigger)

I also tested them without pennies but in that case the cardboard wheel car goes the farthest.:/

On the internet, I found that car with bigger wheels travels the farthest but when I test my cars ironically the car with sprite bottle cap wheels ( which is smaller than cardboard) go speedily and farthest with the pennies.

I don't know what to do. I want to use the one with bottle caps as the final design but I can't explain why its better than the cardboard one. I only have two points of explanation which is because the weight of the car with sprite bottle caps is lesser than the other one it is travelling faster with weights. And also because the sprite bottle caps are thicker.

Please help me explain more to this or suggest me something.

[deleted-189284]

And can I use a pressure gauge (one used to measure blood pressure) to measure the pressure in the balloon? I wanted to keep the same pressure in the balloon while doing the test.

[deleted-2131]

Hi Monadas,

I'm excited to hear that you have some results from testing your two cars! This is wonderful news!

It's OK that the Sprite car goes farther than the cardboard car when it has pennies on it, but that the cardboard car goes farther when there are no pennies involved. This is telling you that the weight of the cars makes a difference. Adding weight to either car will increase the friction force between the car's wheels and the floor. But, it will also change the friction forces between parts of the car itself (e.g., between the axles and the wheels). Depending on the design, the added weight could increase the friction forces among parts of the car by squishing them together. Alternatively, the added weight might push some parts of the car down more than others, which might free up parts of the car that were otherwise touching. Do the wheels of both cars spin the same with and without the weight? Or does the way (or ease with which) the wheels turn change as you add weight to the car?

One way to figure out what is causing you to get different results when they are tested within and without weights would be to look at the cars very carefully with and without the pennies weighing them down. Look for any differences in the way that parts of the car are touching or connected. The differences might be slight, so you'll need to observe carefully. Similarly, you can observe each car as it moves with and without weights on it and try to identify what's different in the ways that the wheels turn or that the parts of the car interact.

The fact that your results are different from what you read somewhere on the internet isn't particularly worrying in this case. Many design factors (besides the wheel size) could be at work and leading to different outcomes. The important thing is to follow your data. It sounds like the sprite bottle with weights is working better. If so, then use that as your final design. If someone asks you why you chose that as your final design, you can explain that the sprite car with pennies traveled farther than the cardboard car with pennies. Doing the careful observing that I talked out in the previous paragraph will help you understand why the sprite car with pennies is going farther.

I'm glad that you want to keep the pressure in the balloon the same in each test. That is an important controlled variable. Using a blood pressure cuff to measure the pressure in the balloon might work. You will need to watch for the pressure in the cuff at which the cuff just barely starts to compress the balloon. Then release pressure slowly until the balloon isn't compressed. The idea is that you want the pressure in the blood pressure cuff to exactly balance the pressure in the balloon. Then you can read the pressure off the blood pressure cuff.

Post back as you have other questions!

[deleted-189284]

Hi, tdaly,
Ok so I am using the sprite bottle car as my final design.
I realized that when weight is added the cardboard wheels take longer to rotate because of their diameter. It requires more force to accelerate a larger wheel. A small wheel is easier to spin with weights. Also the weight of the wheels/ car made a difference. The sprite car was 30 g and cardboard one was around 40. I can also explain in my explanation that smaller wheel would cost less which would relate to the problem I stated in my project.
So I am calculating time, speed and acceleration. Is there anything else I can calculate with the data I have??? Or is this much ok??

Again thank you for your explanation!

[deleted-189284]

And also what to put in the review of lierature part of the project report?
My report only has to contain a title page, table of contents, abstract, review of literature and citations.

[deleted-2131]

Hi Monadas,

I'm glad you were able to settle on a final design. The analysis that you've done sounds sufficient to me. But, you should definitely double check the instructions that your teacher gave you to make sure that you haven't missed something that your teacher asked you to include.

For your review of literature, you could talk about one-dimensional motions (kinematics), friction, and propulsion. You could also discuss some of the factors you chose to include as design criteria.

Post back as you have other questions. I won't be responding to posts tomorrow (Sunday), but I will be back again on Monday.

[deleted-189284]

Hi tdaly,
I just wanted to thank you for your guidance throughout the project! My presentation was good and your guidance was very much helpful.
Thank you

[terikdaly]

Hi Monadas,

You are very welcome. I'm glad to hear that your project turned out well!