How Many Balloons Does It Take to Lift a Little Girl?

A little girl holds a large number of weather balloons. How many are too dangerous, so that she starts to "fly"? Select a number of balloons and click the "up" button to find out.


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The density of air is and for helium it is . The diameter of a weather balloon is . The buoyancy force is equal to the weight of the displaced fluid . The weight of the girl is . Then around 88 balloons are needed to lift the girl.
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