Well, the answer is to divide the results that Mechanica gives you by the
sqrt(386 in/sec^2). BTW, adding a gravity load to the model did not change
the results. I guess what I don't understand is why this is not documented
in the directions for simpletons like myself. Secondly, since I have to
divide by the square root of gravity, it means that Mechanica is not giving
frequency results in cycles per second; which by the way is what PTC's
documentation says!