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As with most substances, air expands when heated. When the same mass of a substance takes up more space, it is lighter.
This allows hot air to rise above cold air, as we can discover if we lie on the floor and then stand on a chair near the ceiling - the difference is often very noticeable.
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What causes hot air balloons to fly?
Usually only balloons that are filled with helium will float. Helium is a gas that is lighter than air, so causes the balloon to fly. Note that if you blow a balloon yourself, it will just float to the ground. There are also hot air balloons in which the air is heated by an on board heater. Hot air, being lighter than cold air, rises and lifts the balloon. When the air cools, unless it is reheated, the balloon descends.
Why the fire always goes upward?
Heat always rises. Hot air is lighter than cold air. That's science baby.
Air is cold or hot?
Air can be either cold or hot.
Is there such thing as hot air and cold air?
Yes. There is such thing as hot air and cold air
Does hot air move into cold air or does cold air move into hot air?
Both. Since hot air is less dense than cold air, the hot air rises as the cold air falls (i.e. as the cold air displaces the hot air). If you were to dye hot air & then inject it into the center of a room, you would observe the dyed hot air rising. What you may not realize is that gravity draws the (invisible) surrounding dense cold air downwards as it displaces the (visible) less dense dyed hot air. === Previous Posters Answer: Hot air rises
What is in a hot air balloon to make it fly?
Hot air! Hot air is lighter than cold air.
Is hot air liter or heavier than cold air?
Hot air rises, so is lighter than cold air.
What keeps hot air balloons aloft?
the hot air inside the balloon is what's keeping the balloon aloft. the explanation is hot gases or air is lighter than cold air so hot air will rise since it is lighter than the cold air.
When balloons are filled with this they are lighter than air.?
Hot air, hydrogen or helium are lighter than cold air.
When balloons are filled with this they are lighter than air?
Hot air, hydrogen or helium are lighter than cold air.
Why does it have to be hot air and not cold inside the envelope of a hot air balloon?
hot air rises; it is lighter than cool air It does not have to be Hot Air inside the balloon, unless you want that Balloon to rise up.Hot Air is less dense than Cold Air and hence the former is lighter.
Why does got air rise and cold air sink?
Hot air is lighter while cold air is heavier. This results in warm or hot air rising and cool or cold air falls.
Why is warm air lighter than cold air?
Warm air is lighter than cold air because cold air is denser, by dense I mean the particles in cold air are more packed together than it is in warm air. Therefore cold air is heavier which is why warm/hot air always floats above cold air (same thing with hot/warm and cold water). That is why warm/hot air is lighter than cold air.That's the reason why a hot air balloon only goes up when there's something producing hot air (like fire for example), and the only reason it goes back down is if you put out the fire. Remember this only happens because Hot water/air is less dense than cold air which makes it lighter.
How does heat affect flight?
Hot air is lighter than cold air. If you fill a balloon with hot air, the air inside will be lighter than the air outside and therefore the balloon will rise (until the air inside gets cold again).
Is a hot air balloon lighter or heaver then air?
The actual balloon isn't lighter than air, the only reason hot air balloons rise is because they are filled with hot air, which is lighter and less dense than cold air, causing it to rise. :)
How does hot air balloon travel work?
In very simple terms, hot air is lighter than cold air, so it rises.
What will hot air do to a barometer?
The air will become lighter causing the barometer to fall. the opposite will occur for cold air.
