"Chip Buchholtz" writes:
: I scored a 430...

I got a 480.

I scored a 420, and I think their answer for question 31 is wrong.
I measured from the center of gravity of the load to the fulcrum,
and they measured from the outer edge of the load to the fulcrum.

Right, the correct answer is 60. Not seeing that as an option, I
figured out how they measured it and chose their answer.

Also the question about naturally aspirated pistons was ambiguous.
There were two correct answers, depending on your point of view. The
retreating piston creates a lower pressure inside the cylinder, but
one could argue that both the retracting piston *and* the natural
atmospheric pressure work together to force air into the cylinder.
They marked that one wrong, but I knew I had a 50/50 chance.

I got the balloon one wrong, but I think they're wrong, or at least
ambiguous. For the baloons to be different sizes in the same air
space (as shown), they have to be of different composition, so they
all are in the "same air" and thus atmospheric pressure (PSI) is the
same (14psi at sea level, for example) but the balloons themselves
exert varying pressures on the gasses therein. Had they asked which
had the highest pressure INSIDE the balloon, I would have gotten their
answer. Unless they meant TOTAL pressure exerted by the atmosphere,
in which case they should have asked for that (and in which case, the
contents of the balloons is irrelevent). Or if they assume the
balloons have not yet reached steady state, but that wasn't mentioned
in the problem either.

Or maybe I was just over-analyzing it. The picture does show them in
common air, though. Had they drawn lines between the balloons, to
show them possibly in different air pressures, I would have gotten it
right.