Mystery #4Tier 2air pressure / suction
Why does a vacuum cleaner suck things up?
Switch on a vacuum cleaner and crumbs, dust and bits of fluff leap up off the carpet and vanish into the machine, as if it were reaching out an invisible hand to grab them. But a vacuum cleaner has no hand, no magnet, and nothing that reaches out of its nozzle. So how does it 'suck' your mess up from a distance?
Your guess
A vacuum cleaner has nothing reaching out of it, so what pulls the dust in?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
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