# Homework Help: Fluid mechanics

1. Apr 18, 2007

### *titanium*

Estimate the maximum pressure that would be applied to your hand if oyu were told it out of an open car window while the car travles at 70mph through still ait at 20 degrees c what would be the maximum pressure applied to your hand if the car where a formula one race car travelling at 220mph

I think im suposed ot use the Bernoulli equation but it doesnt work, iv looked at questions in the text book and they are much simpler, on the work sheet iv got I always seem to have too many unknowns.

2. Apr 18, 2007

### gizzy

I HAVE A THERMODYNAMICS QUESTION THAT I NEED ASSISTANCE WITH.

NITROGEN FLOWS THROUGH AN INSULATED PIPE AT A STEADY STATE THROUGH A PARTIALLY OPENED VALVE. THE INSIDE DIAMETER IS 1.5 inch> JUST BEFOR THE VALVE THE UPSTREAM PRESSURE INSIDE THE PIPE WAS Pup =120psia AT A TEMPERATURE OF 12O degrees fahreheit. THE GAS VELOCITY WAS MEASURED TO BE 20 feet per second.
THE PRESSURE ON THE DOWN STREAM SIDE OF THE VALVE WAS MEASURED TO BE P down =20 psia. HOW WOULD YOU OBTSIN THE TEMPERATURE JUST DOWN STREAM OF THE VALVE.

3. Apr 19, 2007

### FredGarvin

Titanium: You need to show some sort of effort on your part.

Gizzy: Do not hijack threads with a different topic. If you need assistance, create your own thread and follow the forum guidelines by showing how you have attempted to do this problem.

Last edited: Apr 19, 2007
4. Apr 23, 2007

### dfx

Bernoulli would be correct. Think about it, Bernoulli can be applied along a certain streamline. Consider a streamline from infinity...

5. May 20, 2007

### fluidman

It s stagnation pressure

What you need to do is to write Bernoulli equation between a far field point and a point on your hand.You will simply get the solution.It s not so complicated.What you need to know extra is the air density at 20°C.You can glance through appendixes of thermodynamics or fluid mechanics text books. good luck!