Simple Hovercraft

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:

91 Responses to “Simple Hovercraft”
1. Aurora Lipper says:

A thumbtack is the same thing as a pushpin.

2. Heather Grimm says:

what is a thumbtack

3. Aurora says:

You need some way to stick the parts together so it’s air-tight. 🙂

4. Melanie Church says:

What if you do not have hot glue? Could regular glue work as well?

5. Alessandra Soares says:

I love the video

6. Aurora says:

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:

The video on how to handle breaking the forces down into their components is here:
http://www.sciencelearningspace.com/2014/10/vector-notation-trigonometry/

and specifics for handling the coefficient of friction is here:
http://www.sciencelearningspace.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!

7. Rosalind Hitchcock says:

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 …

8. Aurora says:

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!

9. Michelle Palmer says:

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.

10. Aurora says:

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!

11. Michelle Palmer says:

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.

12. Aurora says:

My team will connect with you right away!

13. SHIRLEE GRABKO says:

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?

14. Aurora says:

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!

15. Marcelene Ryan says:

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

16. Aurora says:

The top from a dish soap bottle also works. Look for sport tops on plastic bottles next time you’re in the grocery store…

17. Katie Barr says:

What else could I use instead of a water bottle top because we don’t have any he.

18. Aurora says:

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

20. Valerie Rosenzweig says:

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!

22. Aurora says:

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!

24. Aurora says:

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.

25. jennifer lutz says:

hi I just built my hovercraft but it is not working

26. Aurora says:

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.

27. Lynn Glasheen says:

When will the Arduino projects come out?

28. Ashanta Ambush says:

I like it

29. Ed Foster says:

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

30. R says:

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!

31. Sheri Kelly says:

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

32. Michelle McCartney says:

This was successful, fast, and fun!

33. Eileen Gardner says:

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.

34. Jordan Scott says:

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!

35. Aurora says:

Yes, absolutely! There’s a shot in the video of it gliding across the table. Did it work for you? 🙂

36. Derrick Ramsey says:

did it work

37. Derrick Ramsey says:

Jill Mayer- Did the soap bottle to work well?

38. reptilewill says:

very nice but hey im 15

and i love this website!

39. Liam Fishman says:

The hovercraft looks so cool!! I”m going to try it right now!

40. Lynn Glasheen says:

It was really cool and it works very well.

41. Aurora says:

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:

http://www.sciencelearningspace.com/getting-started/syllabus-schedule/

Let me know if you have any questions.

Aurora

42. Laura Dotson says:

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?

43. Laura Dotson says:

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

45. Aurora says:

I posted an explanation around air pressure right under the video, so you don’t have to wait for the notes about Bernoulli.

46. Christine Groenewald says:

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)

47. Aurora says:

We’re putting together a section on Bernoulli’s principle and air pressure dynamics – look for it in our Flight Lab this summer. 🙂

48. Aurora says:

It’s currently under construction. You will find it in the Flight Lab this summer. Sorry for the trouble!

49. Loree Jones says:

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?

50. Loree Jones says:

Where is the reading on air pressure, or the audio teleclass on Bernoulli’s principles? I tried to find it, but got lost 🙂

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.

51. Mary Thomas Jackson says:

AWESOME! 😀

52. Mia Curlin says:

wooooooooooooooooooooooooooooooooooooooooooooooooooowww!! how did she come up with this stuff???!!

53. Margot Keyes says:

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!

54. Aurora says:

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!

55. Shelli Hutchison says:

The bottle cap keeps popping off. Any ideas?

56. Deborah Rossel says:

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

57. Aurora says:

Duct tape? Although if you use tape, you’ll have to re-tape it each time, but it might be worth it…

58. MJ Wixsom says:

we can not the balloon to stay on ;(
can you help ?

59. Aurora says:

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.

60. Lorelei Grecian says:

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.

61. Tammy Kuempel says:

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!)

62. Aurora says:

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.

63. Helen Morton says:

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.

64. Aurora says:

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!

65. teresa walker says:

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

66. Melissa Akins says:

My 3 children loved this project! Thanks for all you do to help us to educate our children!

67. Jennie says:

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

68. Germaine Rysdahl says:

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

69. Aurora says:

Great idea! I’ll see what I can do…

70. Patti Heseltine says:

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!

71. Aurora says:

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?

72. Mary Raymond says:

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 .

73. Aurora says:

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! 🙂

74. Kimberly Cortez says:

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 🙂

75. shannon flaherty says:

Ours worked best with a cup instead of an index card. The boys are having races right now. 🙂

76. Missy Meskell says:

You can use a regular bottle cap too. You just nedd 7-9 holes instead of 3-4.

77. Aurora says:

78. T.N. says:

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.

79. Math Nut says:

This experiment should call for a few extra paper cups so you can bat your hovercraft back and forth across the table…

80. lori watts says:

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.

81. Dawn Del Rossi says:

we found that we didn’t need the cup and it worked better to open the sports bottle top just a little.

82. Cecilia Savage says:

this is so cooooooooooooool

83. Jill Mayer says:

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

84. Kim Reid Kuhn says:

i am having fun!

85. Denall Moore says:

New favorite sound: “(excited laughter, followed by) That was awesome mom!!”
thanks Aurora!!

86. Carolyn pecharka says:

this is cool i love it Sully 10

87. Carolyn pecharka says:

this is so cool thanks Emma 12

88. Sharon Baloue says:

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)

89. Irene Riley says:

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!

90. Heather Smith says:

I love the video

91. Susan Fox Durand says:

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…