How will two dangling vertical sheets of paper move when you blow between them?

Question

Try it and see and explain it to me! Just wondering if everyone gets the same result. Thanks!

Answer 1

They will move closer. It's a Bernoulli's principle.

Answer 2

That one is easy. It is a Bernoulli's principle exercise.

The principle states that the energy in a column of fluid remains constant. It the column of air is moving, then part of the energy is kinetic and there is a drop in the pressure energy.

So when you blow between the two sheets, the air pressure between the sheets drops and the sheets are pushed together by the outside air pressure

For more fun, take a glass of water and two drinking straws. Place one straw upright in the water.Use the other straw to blow a column of air across the top of the upright straw. Blow fast enough and you can spray everyone in the room.

Answer 3

towards each other. when you have a fluid moving faster than its relative surroundings, it creates a low pressure system around it, and the two pieces of paper will be pushed towards that low pressure system by the relative high pressure of the atmosphere.