Hovercraft transport people and their stuff across ice, grass, swamp, water, and land. Also known as the Air Cushioned Vehicle (ACV), these machines use air to greatly reduce the sliding friction between the bottom of the vehicle (the skirt) and the ground. This is a great example of how lubrication works – most people think of oil as the only way to reduce sliding friction, but gases work well if done right.
In this case, the readily-available air is shoved downward by the pressure inside of balloon. This air flows down through the nozzle and out the bottom, under the CD, lifting it slightly as it goes and creating a thin layer for the CD to float on.
Although this particular hovercraft only has a 'hovering' option, I'm sure you can quickly figure out how to add a 'thruster' to make it zoom down the table! (Hint - you will need to add a second balloon!)
Here's what you need:
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In this case, the readily-available air is shoved downward by the pressure inside of balloon. This air flows down through the nozzle and out the bottom, under the CD, lifting it slightly as it goes and creating a thin layer for the CD to float on.
Although this particular hovercraft only has a 'hovering' option, I'm sure you can quickly figure out how to add a 'thruster' to make it zoom down the table! (Hint - you will need to add a second balloon!)
Here's what you need:
Please login or register to read the rest of this content.
Please login or register to read the rest of this content.
Does it matter the size of the tack?
Any 7-9″ latex balloon will work!
Does it matter what ballon you use?
Hot glue!
Would it be better u used hot glue or regular super glue?
So the air leaks out slow enough to be useful in hovering.
Watch the video and see how it’s used. 🙂
how come u need a tack?
Why would you need some holes when doing this experiment??
A thumbtack is the same thing as a pushpin.
what is a thumbtack
You need some way to stick the parts together so it’s air-tight. 🙂
What if you do not have hot glue? Could regular glue work as well?
I love the video
Thanks for reaching out for help! You’re actually working a pretty advanced problem – most college level students tackle this one during their first or second year in engineering/physics classes. Let me see if I can help.
First, the answers are posted on the last page of the worksheet. However, there isn’t a step-by-step solution shown here for this particular problem. You’ll find those videos in this section:
https://www.sciencelearningspace2.com/category/advanced-physics/newtons-laws-2/forces/
The video on how to handle breaking the forces down into their components is here:
https://www.sciencelearningspace2.com/2014/10/vector-notation-trigonometry/
and specifics for handling the coefficient of friction is here:
https://www.sciencelearningspace2.com/2014/10/static-and-kinetic-friction/
The units for force are always in N (Newtons), which is kg m/s2, so it sounds like you found a type somewhere. The equations used in this lab are F=ma and f=μk
Let me know if I can help more!
Hi Aurora, we’re working through the advanced lab worksheet, and some of the math in there is new and extremely daunting. My son has been at it for a few hours, but we also have no way of knowing whether the answers are correct, other than the “reasonable-ness” test (which is hard, when we don’t have trained intuition on units like kg m/s^2 :).
Is there a worked example anywhere of a similar problem? We have taken detailed notes on all the lectures in the AP Physics program up to this point, but can’t find all the materials necessary to get to a solution. One specific example: we get to the point where we need to calculate Fk, but the units for Fg are in kg m/s^2, and the units for Fnet are in m/s^2 (per note in the lab “Fnet is equal to the acceleration …”). How can we subtract given dissimilar units? We think that might be incorrect, as Fnet must also consider mass, right?
My son is continuing to pound away at this, but a worked example would be tremendously helpful. This is by far the most challenging problem we’ve hit so far …
Yes, you are correct. Newton’s 3rd law of equal and opposite forces makes the car move forward. The elastic potential energy of the balloon (being stretched beyond its normal resting state by the air inside) transforms into moving (kinetic) energy of the car. Great job!
Hi Aurora, this is a fun experiment thank you.
I’m trying to line the experiments up with the scientific concepts they are supposed to learn.
It looks like this uses: Newton’s 3rd Law, sum of forces, kinetic energy, potential energy (before you release the balloon?), when two objects interact.
Am I missing anything? Thank you.
The “Advanced Students Lab” is available for folks with the upper level subscription to the program. It’s intended to be full lab work for high school level students that have completed algebra and started on geometry or trigonometry. You can try it, and if it’s too much, then try a different experiment.
Most of the lab sheets (there’s over 700 of them) are for K-8 students – those are usually right under the video and say “Download your Lab Worksheet here”. I don’t think this experiment has one, but you’re welcome to download the advanced one if you have access to it and modify it so he can use it to record his data from the experiment (just don’t bother with the harder calculations). Hope this helps you decide if this is a good fit for your teen!
I see I can go to the “advanced students” lab. I was wondering if that option will come up again in a later unit or if I should do it now. My son is 13 years old. I don’t want to throw too much stuff at him and make it overwhelming. Thanks.
My team will connect with you right away!
I had access to the hover craft video in an email 3/12/2015 but find that I cannot access that video again. What happened?
Were you able to get the balloon to stand up on its own when fully inflated and on the tip of the cap? How big is your balloon? (You’ll want one 7-9″ in size.) You need to figure out a way (like a real scientist does!) to get the balloon to stand up… that’s why I used a cup, but there’s a lot of different ways you can accomplish this. Use your creative inventive and critical thinking skills to figure out how to keep that balloon upright. ANd send me a photo!
We had all of the materials and we watched the demonstration 4 times but our balloon kept flopping over and it wouldn’t hover at all. How could we modify it so that it would hover?
P.S. we did poke the holes through the sports bottle top
The top from a dish soap bottle also works. Look for sport tops on plastic bottles next time you’re in the grocery store…
What else could I use instead of a water bottle top because we don’t have any he.
Oops! Sorry about that. We’re updating the videos in Unit 1 this week and it looks like my programmer goofed. We’ll get this fixed right away.
We watched this video last week and were missing a part and had to buy it over the weekend. Now the video is diferent. It isn’t the simple hovercraft anymore, its the 32 minute advanced hovercraft
It was a lot of fun, thank you! We are definitely going back for more experiments! Still trying to figure out thruster part of it….hmmmm. Max, age 10 and mom
I got it going in Safari, so problem solved. Weird, because Firefox had no problem until this particular video. Thanks!
What device and browser (do you have the latest version?) are you using?
The video is not playing for me and there is no procedure written to follow. My kids really want to do this experiment. Help!
Can you tell me more about what’s going on? When you say “it’s not working”, what specifically is it doing or not doing? Tell me as much as you can so I can understand what’s going on for you.
hi I just built my hovercraft but it is not working
They will be part of the Advanced summer e-Camp program, which is released in the summer. It’s going to be so much fun! There are two different robots with different sensors and all kinds of neat things to learn.
When will the Arduino projects come out?
I like it
This was such a fun experiment! My 13 and 8 yo both had fun. Thanks for such an engaging program, Aurora.
Kudos from The Foster Fam
My children have been in love with the whole program, so much so that I have to use it as a reward for doing other subjects and chores!
My 13 year old has been doing all the electronics labs and experiments and making up his own projects with the knowledge he’s gained. He even dug up parts of old computers that we quit using because they didn’t work anymore,
fixed them, and built himself a fully functioning (including internet access!) computer that he now uses instead of the family computer – all from parts we had on hand!
My 10 year old has been fascinated with the earth mover and catapults and stripping wires for his brother’s electronics projects.
My 7, 4, and 2 year olds are doing all they can get their hands on. They love the hovercrafts, harmonica, sling shots, and all the simpler stuff from sticks, rubber bands and balloons, besides the underwater robots and
cars galore.
The science they are learning is impressive, not to mention their understanding of the world around them. From what they have been learning, they have recently been explaining to me how the weather works, from what
makes wind to how water flows. Even more, they have been applying this knowledge to practical projects around the house from fixing faucets and drains to draining and dismantling (and troubleshooting problems with) the
swimming pool for the winter!
They love explaining how things work to each other and their parents and grandparents (and anyone who will listen). They especially love it when they can tell it’s stuff the adults have forgotten, if they ever knew it,
despite their own physics and math and other science backgrounds! The children keep explaining, complete with their own examples, until they are sure their audience fully understands. It’s great!
Thank you so much for this program, it’s work the cost!
Great video. Really helped with step-by-step instructions.
Our simple hovercraft worked well, after a few more holes in the cap. We’ll try the more sophisticated one soon, with Dad (our resident Engineer).
I’m glad I can at least get my 3 daughters jazzed about science. It becomes the topic of many conversations…the options are endless! Thanks, Aurora.
Sheri Kelly
This was successful, fast, and fun!
My 10 year old son made this today. He adapted a different kind of sports cap. He couldn’t get the balloon down through the toilet roll tube, so instead he used a little medicine cup. This was small enough to get the stalk of the balloon through it, but large enough to prevent the balloon from falling sideways and creating extra friction on the table. It worked really well on a smooth surface (not on the floor, with the breaks between the tiles). We talked about how it worked.
We loved it! Had the neighbors over and did this. Love how quick, easy and educational this was! Next we try the one with motors, foam, propellers … we’re moving up!
Yes, absolutely! There’s a shot in the video of it gliding across the table. Did it work for you? 🙂
did it work
Jill Mayer- Did the soap bottle to work well?
very nice but hey im 15
and i love this website!
The hovercraft looks so cool!! I”m going to try it right now!
It was really cool and it works very well.
That’s a great question, and one that deserves a thorough answer…because we know that while experiments can be fun and engaging, they alone “do not a curriculum make”. I’ve dedicated an entire section to addressing this concern here:
https://www.sciencelearningspace2.com/getting-started/syllabus-schedule/
Let me know if you have any questions.
Aurora
hi do you have a suggestion for how to make it fly across the room?i tried my idea and am having trouble can you help?
hi do you have a suggestion for how to make it fly across the room? i have an idea and am trying it out right now.
T.N. says:
Friday at 4:16 pm
Firstly, let us say that we appreciate your approach to science education, and although we’ve only begun we believe this will be an asset to our girls who are 10 and 8. We would like to ask how you approach converting the fun experimental wow factor into the kind of knowledge they will be expected to know on tests and in life? That is, we think it will be easy for them to remember a homemade “hover craft” for example, but will they understand the scientific principles that make it work? In short, how do we link the fun with the drier side of science…facts, figures and formulas
I posted an explanation around air pressure right under the video, so you don’t have to wait for the notes about Bernoulli.
Thank you auntie aurora
it worked really great-
iera-michelle (6yrs)
Thanks auntie Aurora,the hovercraft experiment was sooooooooooooooooooooooooooooooooooooooooooo cool!!!!
Stephan (9yrs)
Thanx for making it so much fun. It definitely helps to get them wondering about the principles behind the fun stuff.
Christine (mom)
We’re putting together a section on Bernoulli’s principle and air pressure dynamics – look for it in our Flight Lab this summer. 🙂
It’s currently under construction. You will find it in the Flight Lab this summer. Sorry for the trouble!
sorry for the typos…I was trying to say that it would be more user friendly to have a topical reading link on the experiment page.
Does anyone out there know where to find the reading for this experiment, or is the paragraph at the top of the page it?
Where is the reading on air pressure, or the audio teleclass on Bernoulli’s principles? I tried to find it, but got lost 🙂
I did see some reading about Bernoulli in one of your comments above.
I agree that it most be mom and kid friendly to have the subject reading linked to the experiment page.
I’m trying out E Science for the first time. The Hovercraft is going to be our first activity.
AWESOME! 😀
-Charli(7th grader)
wooooooooooooooooooooooooooooooooooooooooooooooooooowww!! how did she come up with this stuff???!!
We actually tried this many times, before deciding to forgo the cup/paper altogether. Then attaching the balloon straight onto the bottle top worked wonderfully! Especially on our glass topped stove, but almost as well on our kitchen table. The girls loved the OOH-AHH factor, and learning about physics and air pressure was super fun! Keep the fun experiments coming Aurora!! Thank you!
Is the balloon coming off the bottle top, or is the top coming off the CD? For the first case, try a balloon with a smaller neck; the second case needs more hot glue!
The bottle cap keeps popping off. Any ideas?
it is so easy! our mom works and we log on and see what we can find to do today. we had so much fun with this experiment. thanks so much aurora!
love&peace,
deborah rossel’s 3 kids
Duct tape? Although if you use tape, you’ll have to re-tape it each time, but it might be worth it…
we can not the balloon to stay on ;(
can you help ?
I’m glad you got it working! If you ever have trouble getting something to work, let us know so we can help. Science is supposed to be fun, but it can get frustrating sometimes, I know.
We jimmi-rigged it util we could get it to work. Thank you for encouraging us that these experiments do work as we’ve tried many that haven’t.
this is one of the forst experiments we’ve done, and it worked out really well! the best place we found to glide it was on our flat topped stove(talk about smooth!)
Are you looking for Bernoulli’s principle defined? Unit 20 (to be released soon) is all about air pressure and fluid dynamics, which cover’s Bernoulli’s as well. Here’s an excerpt from the section about why airplanes fly that I am still working on:
The wings on an airplane use an idea from an Italian scientist named Bernoulli, and his idea was this: the faster air flows, the less time it has to push down on the surface and because of this, the air pressure is lowered.
An airplane wing has a curved surface on top to get the wind to move over the top faster, which decreases the pressure over the top of the wing. Just like with the ping pong ball in the funnel, where the air moved the fastest was where the pressure was lowest. On an airplane wing, the lower air pressure is on the top of the wing. Since higher pressure is now on the bottom surface, and higher pressure always pushes, the wings (and also the whole airplane) go up.
When you referred to the audio teleclass on Bernoulli’s principles on one of comments as to the scientific principles to look into regarding the hovercraft, was that part of Unit 1: Mechanics: Force, Friction, & Gravity teleclass? Thanks.
It’s simple to do – you blow up the balloon and use a large piece of tape to tape the neck of the balloon to either the top surface of the CD or the side of the cup. If it’s off-center, then your hovercraft will spin (which can be fun), so be fure to get it as close to the center line of the CD as possible!
Hi Aurora, Thanks for so many awesome experiments. You mentioned adding a thruster to the hovercraft by adding a second balloon – can you please elaborate on that? We can’t quite figure how to attach it . Thanks
My 3 children loved this project! Thanks for all you do to help us to educate our children!
We wanted you to know that we tried the punching balloon and it was fun. Our original hovercraft had a few modifications so our findings will not necessarily be the same as anybody else. Our modifications include, using a spout off a reusable sports bottle that was larger on the bottom and smaller on top than one requested for a 2 liter, a plastic cup instead of paper, and we used a DVD that had a label on it. All of these “modifications” surely added weight to the experiment.
The punching balloon has a larger “stem” on it so we added adhesive tape around the the spout to give the balloon a larger surface area to grab onto. We had to adjust this because it added weight to the hovercraft. Our cup had to be cut a couple of times for various heights because the stem of the balloon is much longer than a regular balloon. What we discovered was when all the pieces were too heavy, nothing hovered. Before final adjustments, the balloon would sometimes fall on its side the then hovercraft would just spin in circles. The final adjustments proved that the hovercraft would zoom along for much longer and a little quicker than a regular balloon.
My 11 year old wants you to know that it requires two people to to attach the larger balloon 🙂 I let him know that you have much more experience, so you may be able to handle it.
Thanks we had fun and we are looking forward to Summer Camp tomorrow,
Jennie
After we viewed the video explaining how to make the hovercraft, my daughter said, “OK, let’s do it!” Then we did it. Thank you! I am looking forward to a great hands-on learning summer with three plus + kids!
gigi
Great idea! I’ll see what I can do…
We are really enjoying the experiments.Thank you!
I agree with others that it would be EXCELLENT if under each video you would include a link to where we can find the information on the forces at work or other educational material that goes along with it. The links would really help save time trying to look things up. Parents may not always even know what to look up to explain the forces at work for each experiment. Thanks again!
Make sure there’s air coming out of the tiny holes you punched. The biggest problem we usually find is that there’s a bump or something dragging on the table – it’s GOT to be smooth. Can you send us a picture?
My hovercraft does not work well, I have tried all the things you suggested plus more..Could it be the weight of the cup I am needing to use, as we are unable to find the paper cups where we live in Mexico and are using styro foam cups .
please help
Thanks for your feedback! And yes, we really do try to have as much content in the right place where you need it. For questions, you’ve got it perfect – ANY questions you have just type in these comment fields and you’ll get a response zipped back to you.
For air pressure and Bernoulli’s principles, you’ll find a BIG section on that released June 1st with our e-Camp in our Aerodynamics Unit. I can certainly put a link to it from the hovercraft page when it’s published, but we really don’t get into the mechanics of it until that section.
If you have more questions, don’t hesitate to ask! 🙂
First of all, let me say that my boys absolutely love the experiments on this site (1st and 2nd grade). My oldest LOVES science and until now, I have not had the time to pull together science experiments (which he asks to do daily). I love his interest in science and this is a great way to foster that interest. He also loves to research the answers to his questions. If I have reading materials available or videos that answer his questions, he is very self-directed in finding the answers and then sharing them with his brother.
That being said, it would be great if you had links to the teaching material somewhere on the page near the experiment video. For example, links to a reading on air pressure, or the audio teleclass on Bernoulli’s principles, or even how to start measuring things like speed. This would be a great help instead of having to search the site or the web to find the answers to the questions.
Keep up the great work on such a fun site 🙂
Ours worked best with a cup instead of an index card. The boys are having races right now. 🙂
You can use a regular bottle cap too. You just nedd 7-9 holes instead of 3-4.
Great question! And yes, the kids readily gobble up projects like hovercraft, sling-shot helicopters, etc. but what are they really learning? We use the experiments as a hook – for example, we would start a lesson by building something really cool – like a hovercraft, and then when they’ve played around with it a bit, they’re going to start asking questions like – how does it hover? Why does it rotate this way every time we launch it? How can we make it go faster? Etc..etc… This signals you that they are ready for the more academic side of things, so you’d pull out the reading on air pressure, or the audio teleclass on Bernoulli’s principles, or even talk to them about how to start measuring things (how do you know you’re going faster if you’re nit measuring things? And how will you measure speed is a totally great question to answer! It’s all based on stuff they’re going to encounter in real life, but the main difference is how to deliver it – I don’t recommend cracking open a text and reading dry paragraphs first… rather start with the juicy, fun, exciting stuff which will naturally spark their curiosity and lead them to better questions and hungry for more. That’s the way the real world is, after all. Does that help?
Firstly, let us say that we appreciate your approach to science education, and although we’ve only begun we believe this will be an asset to our girls who are 10 and 8. We would like to ask how you approach converting the fun experimental wow factor into the kind of knowledge they will be expected to know on tests and in life? That is, we think it will be easy for them to remember a homemade “hover craft” for example, but will they understand the scientific principles that make it work? In short, how do we link the fun with the drier side of science…facts, figures and formulas.
This experiment should call for a few extra paper cups so you can bat your hovercraft back and forth across the table…
We loved this experiment! I have KG, 1st and 3rd. So we watched Magic School Bus “air” and it fit very well with this experiment.
we found that we didn’t need the cup and it worked better to open the sports bottle top just a little.
this is so cooooooooooooool
This hovercraft is AMAZING!!!!!!!!!!!!!!! I recommend this experiment to any person who is learning about physics. We didn’t have a sports bottle top but we used a dish soap bottle top.
-Parker+Greta
i am having fun!
New favorite sound: “(excited laughter, followed by) That was awesome mom!!”
thanks Aurora!!
this is cool i love it Sully 10
this is so cool thanks Emma 12
We tried this and it works. We did have to make extra holes and we used a glass table top. Great experiment and easy to do. (Mom)
I LOVE IT!!!!! (Son)
Love the hovercraft project! My five year old was (and still is hours later) excited about experiments. He wants MORE SCIENCE and so do I (even my three year old was involved)! I’m terrible with projects and this was my first try with your material. What didn’t work at first was a great opportunity to problem solve with my kids. We did get the hovercraft to work just like the video. Wow! I actually made something work. You are the coolest!
I love the video
Thanks for adding these simple experiments to the main site…Before it was so hard to find them..I love that you have them all under getting started…