How Do Hot Air Balloons Work?

Sometimes on a nice clear day, we can see
something special in the sky … … a hot air balloon! Have you ever seen one? Have you ever wondered how a hot air balloon
works? How does it get up there? And how does it /stay/ up there? Well, it’s all about the air! There’s nothing special inside the balloon
that makes it float. It’s just the same air that we’re breathing
right now! So how does /that/ keep the balloon up there? Well, even though you can’t see it, air
isn’t /nothing/–it’s /something/. Air is made of matter! Anything that you can touch, or feel, or that
takes up space, is made of matter. So air is made of matter, just like water
is made of matter, and so are the clothes you’re wearing, and the food you eat — even
your body is made of matter! So what kind of stuff is matter made of? It’s made of tiny things called molecules. These are little particles that are way too
small to see, but they’re there! So both inside and outside the balloon, there
are many molecules of air, moving around and taking up space. But you know what’s fun about molecules? When they heat up, they start to move differently! That’s right! When something gets warm, the molecules that
it’s made of start to move around /faster/, bouncing around and spreading out. And that’s the important part: They spread
out. So let’s think about how that would happen
in a hot air balloon. When the balloon is on the ground and ready
to go, it has some air inside it. And that air is the same temperature as the
air /outside/ of the balloon. So the air molecules are all moving around
at the same speed, and are just as far apart from each other, both inside and outside of
the balloon. But /then/, the balloon pilot makes the air
/inside/ the hot air balloon … hot! You see, these balloons don’t have engines
like airplanes do. They have big heaters that send flames up
into the balloon!! So when the pilot turns on the flames, it
heats up the air /inside/ it! That makes the molecules of air start bouncing
around inside, and they start to get further apart from each other. As these molecules spread out, they start
to fill up the balloon even more! And when those molecules of air /inside/ the
balloon start to take up more space, we say that the air becomes less dense. Soon, the air inside the balloon becomes less
dense than the air /outside/. Now, maybe you remember when we talked about
why some things float, and other things sink. We learned that things that are less dense
than /water/ will float to the top, while things that are more dense will sink. And the same is true with our balloon! The hot air /inside/ the balloon is less dense
than the cool air /outside/ — so the balloon can float up! In fact, warm air /always/ floats up. Have you ever noticed that in the winter,
when you have a heater on, the downstairs of your house is usually a lot cooler than
the upstairs? That’s because the warm air in your house
is rising to the top! So, in a hot air balloon, the hot, less-dense
air inside the balloon rises up on top of the cooler, denser air outside. And that makes the balloon rise! Now, how does the balloon get back down? Well, the pilot opens a flap at the top of
the balloon that lets the hot air out! As the balloon fills with cooler, denser air,
it begins to sink gently back down to the ground. It may be hard to believe that something so
big can be carried by little molecules we can’t even see. But that’s what makes hot air balloons — and
science! — so amazing! Do you have a question about anything else
that floats or flies? Do you want to know how something works? Then ask a grownup for help, and leave us
a comment below, or send an email to [email protected]! We’ll see you next time!

80 thoughts on “How Do Hot Air Balloons Work?”

  1. Less density materials float above denser materials because gravity pulls the denser material with a stronger force.
    And I derived this conclusion by learning physics, I didn't learned this particular thing, it's just very intuitive logic stuff.

  2. So interesting!! πŸ™‚
    Thank you!

    I'm 16, and I still don't understand how the air ballons works.
    HaHa …
    Now I know, and I can teach my nephew about this.

    Thanks, again.

    $Ucess !!!

  3. What a great video! My class is reading about hot air balloons and we started watching some videos on youtube to get a better idea. We love your channel and especially how fun you are!

  4. Wow and thanks for the information πŸ‘πŸ½πŸ‘πŸ‘πŸ‘πŸ‘ŠπŸ˜€πŸ˜„

  5. MATTER = 10000000000000000 MOLECULES MOLECULE = 8901939494948383493 ATOMS ATOM = 1839485984948494829484949495959 QUARKS

  6. Actually to go down you let the balloon cool and don’t add flames, you only pull the top when you are taking the balloon dpwm

  7. Why Hot air goes upside surrounding with cold air ??? As we know that density & viscosity will increase with increase the temperature for Gases/Air (just opposite to liquids)
    Please Justify….???

  8. when you heat the inside it goes faster your giving the molecules energy like melting ice you turning it from solid to liqid

  9. But there some air baloon( the small one for kids to grab with rope) usually use helium,or hydrogen and its not being heat up.. its right they're lighter than Oxy, but why They'renot affected to gravity

  10. An atom alone is not a molecule also most of the stuff in air are elements so not that many molecules are in the air compared to single atoms I'm in 9th grade and know this please be accurate

  11. Wrong information !!!!!!!!!!!! When the air inside the balloon get hot it will be less weight this is correct .. but what is wrong is not the hot air what makes the balloon fly .. its the air under and outside the balloon pushing it up because the balloon has hot air inside .. this is correct .

  12. wow…. she is way too plain. put some makeup on… put some color on your lips!!!! she literally looks like a corpse!!!

  13. Hot Air Balloon – Prep, Take Off , Flight and Landing @
    If you like or watch this video, you will definitely love this latest HD video on same subject and concept 😍😘😍

  14. Hotness inside a balloon in the bottom side can move balloons upward. It is not air pressure it is high heat at the bottom side. not in the center or top of the balloon. right?
    Fire operated balloons work in the same way. Why? because light objects have to move away from the flames of fire. They put fire under or at the bottom of the balloon then the balloon flays. It has nothing to do with air pressure or heat pressure.
    Example: create fire near the trees leafs then the life moves away from the fire.
    Right? thanks.

Leave a Reply

Your email address will not be published. Required fields are marked *