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Monday, February 01, 2010

Chewing gum and helium experiment

There is a YouTube video about an experiment with gum and helium, creating a balloon that can lift a person.

Using the law of hydrostatics, the driving force must be at least equal (as can be seen in a certain part of the video) to the weight of the man with the balloon..

So,

P = I

Replacing the weights by m g and knowing that clip_image002[6]

 

we have

clip_image002

The mass of the man will be

clip_image004

Substituting the values

clip_image002[8]and

clip_image002[10]

we obtain

clip_image006

and we can drawing the graph mH = mH(R)

clip_image008

We have, for a mass exceeding 65 kg, the diameter of the balloon will be greater than 5 m.Therefore, by observing the video, is not the case.

The person has a high less than 2 m, the diameter of the ballon is much less than 2 m.

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