# Re: pressure and fortran

In article <86ulj7Ff3dU1@xxxxxxxxxxxxxxxxxx>, Uno <merrilljensen@xxxxx>
wrote:

implicit none

real :: mile_in_feet, atm_per_mile, atmos

mile_in_feet = 5280

This is feet per mile, right?

atm_per_mile = 32.808399169

This is feet per atmosphere, right?

atmos = mile_in_feet / atm_per_mile

This is atmospheres per mile, right? Your variable names are a little
confusing.

print *, "atmos is ", atmos

endprogram
! gfortran -Wall -Wextra p1.f90 -o out.exe

q1) Consider a half-inch copper pipe. Temperature is constant. If you
ran it for a minute into a pool, you would get a certain volume, say, x.
If you ran it for a minute at 32.8 ft below water level, what volume
of spewed water results?

You cannot know. If the pressure within the pipe is greater than the
pressure at 32.8 ft, then the liquid will continue to flow, but at a
slower rate. If the pressure within the pipe is less than the pressure
at 32.8 ft, then it will flow in the opposite direction.

So you need an additional important piece of information to answer the
question.

q2) How would this vary if salt were added in the amounts of the gulf
of mexico?

You need to look up the density of sea water and compare that to fresh
water. You can then determine the feet per atmosphere of pressure for
sea water, and that should give you enough info to answer the question.

\$.02 -Ron Shepard
.