Objects Lighter Than Air

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Objects Lighter Than Air People have always been fascinated with the idea of flying, so when Joseph Michel Montgolfier invented the first hot air balloon in 1783, it became pretty popular. As time progressed, the construction of the hot air balloon evolved. People tested new ways to improve it to where it would be able to fly higher and for longer distances. There are a few main principles that go into making a hot air balloon fly including air pressure and buoyancy. Buoyancy is one principle that causes a hot air balloon to fly. It is an upward force that pushes things into the air. However, the weight of an object must be less than or equal to the buoyant force so that object will float. An object like a balloon, must weigh less than the air it displaces. In order to do so, the balloon has to be filled with air that is not as dense than the air around it. The buoyant force would lift the balloon, but the air pressure would have to be kept the same. Air pressure is another significant principle that goes into making a hot air balloon fly. Air pressure is caused by gas particles colliding frequently into each other as well as into the walls of what is containing it, in this case, a balloon. The amount of air pressure depends on how often these particles collide. For a balloon to fly, the air pressure needs to be high, at least as high as the outside air pressure otherwise it would crush it. There are a few ways to increase air pressure including adding more gas particles to increase the frequency of collisions or raising the temperature of the air to speed up the particles which in turn would result in more collisions and greater air pressure. Since it is important that the air is heated up, it also helps if the outside air is cooler so that there does not have to be as many gas particles to create the same high air pressure. Overall, buoyancy and air pressure
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