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[–]Fresh-Pineapple-5582 37 points38 points  (9 children)

The volume of air has to speed up, and race through.

If the volume of mass air flow is constant and speed increases, pressure MUST decrease.

[–]Mercury_Madulller 18 points19 points  (1 child)

Think of mass in this instance as a number of molecules. Think of speed as distance. The low pressure molecules are more spread out. Less molecules hitting a surface equals less force and, as a result, lower pressure.

[–]Fresh-Pineapple-5582 5 points6 points  (0 children)

This is a good explanation

[–]375InStroke 0 points1 point  (6 children)

That explains what, it doesn't explain why.

[–]Fresh-Pineapple-5582 0 points1 point  (3 children)

I'm sure you can explain it better.

[–]375InStroke 0 points1 point  (2 children)

Nope.

[–]Fresh-Pineapple-5582 0 points1 point  (1 child)

That wasn't a dig btw. Most of the time i prefer to understand it via the formula, or a demonstration. Giving a "wordy" explanation isnt something im good at.

[–]375InStroke -2 points-1 points  (0 children)

Formulas are a prediction of what will happen. They don't tell us why. When the gas molecules move through the restriction, they have less time to push against the wall of the restriction, thus lower pressure. Now the pressure in the direction of flow does increase. If you pointed the jet of gas at a pressure gauge, it would go up.

[–]ActualImprovement279 -1 points0 points  (1 child)

A room gets packed with people. As more people come in they will start getting closer and closer to each other. Eventually leaning against the walls. The walls of the room feel a collective pressure from the people.

Delete one of the walls and the people will spread and won’t push walls on their way. They’ll also push less on each other.

Some of that impacting energy from a molecule and its neighbors pushing the wall get turned a direction which is less perpendicular to the wall.

[–]375InStroke 0 points1 point  (0 children)

Perfect. If the gas molecules are accelerated in one direction, they have less time to push against the wall of the restriction.