Bernoulli’s Principle seems to say that increased flow velocity causes less pressure. This does make sense, since pressure takes energy and so does motion, so with a fixed amount of energy of course there’s a tradeoff. But in every example I can think of, the opposite seems to be true. If you put your thumb over a hose nozzle, the water goes faster and there’s also increased pressure on your thumb. The higher you turn the water flow, the faster the water flows and the stiffer the hose becomes. What am I missing?
In: Physics
It’s a bit easier to imagine with the [nozzle of a rocket engine](https://en.wikipedia.org/wiki/Rocket_engine_nozzle#/media/File:De_laval_nozzle.svg): The throat of the nozzle throttles the flow of gas out of the combustion chamber, that is why there is a large pressure inside. Inside the nozzle, the gas can expand and speed up, turning the energy from its heat and pressure into kinetic energy.
In the example of the garden hose, your finger is the throat of the nozzle. It restricts flow of water, and therefore increases pressure inside the hose. The gap between the garden hose and your finger, where the water can flow through, is where the water can turn the pressure into kinetic energy.
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