David Bart1E, age 13, of Victoria, B.C..,Canada, for his question:

How does a vacuum c1eaner work?

When you take a cupful of water from a pailful of water, the surrounding liquid flows in to fill up the hole. When you remove some of the air from a room, you create a partial vacuum, and the surrounding air flows in to fill up the empty pocket.

The motor of a vacuum cleaner runs a fan which draws off a stream of air, and the surrounding air flows in to make up the shortage. Fast winds and other air currents are strong enough to bend and even lift solid objects. The air currents flowing into the vacuum cleaner are fast enough and strong enough to drag along dirt and dusty debris.