Modern hot air balloons do not have sand bags because the air input is easily controlled for lift. Hot air balloons used to have sandbags to weigh them down until lift off and sand was gradually dumped to gain height in the air.
hot air balloons and balloons
hot air balloons, colorful ones what kind of simple quesion is this!
helium or oxygen depending on what you put in them
They have to let out the hot air a little at a time.
Gases used are: air (and hot air), helium.
Hot air is used for hot air balloons.
Hot air balloons float because hot air displaces cool air in the atmosphere
air balloons or hot air balloons fly because they fill with a very light type of air. The air is hot air.
hot air balloons
Hot Air Balloons work because of the hot air.The hot air rising stays in the balloon and carries it upward.
This may not help, but I didn't think it had ANYTHING to do with hot-air balloons...
when do hot air balloons cometo bucyrus ohio
Buoyancy allows hot air balloons to fly.
People think that hot air balloons where made for battles.
hot air balloons and balloons
hot air rises
Hot air balloons have a device at the top called a parachute to let the hot air out, controlling their decent.