Mist Blow – demonstrate low pressure effects

Things required

Two straws

A glass of water

Procedure

• This is how you do it – hold one straw vertically in a glass of water with one hand. Don’t let the end of straw inside the water touch the bottom of glass of water as this might block the flow of water.

• With the other hand, hold straw horizontally one tip should be in your mouth and other end should be held near to the open end of the straw that is in the glass at 900 angles.

• Blow as hard as possible.

• If the straws are set properly, the blowing raises the liquid up the vertical straw. When the liquid reaches the top, it comes in line with the dissection of blow.

Inference

The blown air creates a low pressure on the top of vertical straw. Trying to fill this low pressure, the water in the straw rises up to the top of the straw. In this process the water gets in the way of the blown air and is dispersed by the speed of the blown air causing mist.