Which shows a decrease in fluid pressure?

A river speeds up when it moves into a narrower channel.
Water in a creek slows down as it enters a slow-moving river.
A fan is turned from high speed to low speed.
Oxygen is compressed as it is put into a pressurized tank.

Question

Which shows a decrease in fluid pressure?

 	
	A river speeds up when it moves into a narrower channel.
	Water in a creek slows down as it enters a slow-moving river.
	A fan is turned from high speed to low speed.
	Oxygen is compressed as it is put into a pressurized tank.

anonymous · Answer

i want to say a fan is turned from high speed to low speed

anonymous · Answer

thanks i think so too

anonymous · Answer

all the others increase fluid pressure.

anonymous · Answer

ya they are

mrnood · Answer

I think you are all wrong - wait a moment

anonymous · Answer

ok then what is it

mrnood · Answer

I guess you are looking at fluid flow:
Lookat the Bernoulli equation
It shows that faster flowing fluid has a LOWER pressure

SO - a fan turned lower gives slower airflow = higher pressure
The water speeding up in a narrow channel has lower pressure
Look in your book for Bernoulli equation, or venturi

This effect is the main reason planes fly, and the venturi effect is used to create vacuum pumps, and in carburettors