What if...
 Fred |
 Lilly |
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Exactly. But how can those considerations help us? Mmhhh...
The helium balloon is affected by buoyancy in the air in the car. Therefore it rises and must be held by a string, otherwise it would "stick" on the ceiling or fly away. But how does it move while the car is braking? “
The helium balloon is affected by buoyancy in the air in the car. Therefore it rises and must be held by a string, otherwise it would "stick" on the ceiling or fly away. But how does it move while the car is braking? “
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Well, a little while ago we said, that all loose bodies in the car keep on moving in the driving direction while braking because of their inertia. Thus the air must do the same, too! The car slows down, but the air keeps on moving forward!
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And consequently the air is more dense in the front than in the back of the car.
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Right! And the denser air pushes more strongly against the floating balloon than the less dense air.
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As a result there is a force directed backwards. And this means, that the balloon ...
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Wait! I think, I have found the solution.
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You, too? Then answer the brain-teaser!
