[Unified-mailman] F19 mass regrade

[Nivair H. Gabriel]

Hey students,

After looking over F19 (from Problem Set 9) again, I realized that I unfairly
took off a point from a few of you.  The solution for F19, part c. assumes that
air will flow out of the bottle until it is completely evacuated and there is
*nothing* left inside.  Many of you, however, solved for the minimum time while
taking into account the fact that air would flow out of the bottle only until
the pressure inside the bottle was equal to the atmospheric pressure.  This is
a slightly harder way to do it, but certainly more valid, and the problem
statement didn't specify an assumption.

As such, if you solved it that way and I took a point off, please leave your
problem set in my dropbox by the TA office -- I'll add it back and let Christy
and Jenny know.  If you solved it using the first assumption, keep your points;
that is the way the solution solves it, after all.

Finally, sorry I didn't catch this before, and good luck in the Flight
Competition.

cheers,
Nivair


-- 
Nivair H. Gabriel
Aeronautical/Astronautical Engineering
Class of 2008
Massachusetts Institute of Technology

http://web.mit.edu/nivair/www/

DO ONE THING EVERY DAY THAT SCARES YOU.
- Eleanor Roosevelt