Reading this question Why are rocket engines operating above 100% often considered nominal? leads me to a question about throttling back the SSMEs in the later stages of a Shuttle Launch to limit G forces on the astronauts. If the SSMEs were not throttled back, what would have been the anticipated G Forces on the astronauts at the end of the main SSME burn time?
(3 x (490,000) lbf / 308650 lbm ) = ~ 4.75 g's
(3 x (.65 x 490,000) lbf / 308650 lbm ) = ~ 3.1 g's
Using the approximate 65% power level at shutdown, assuming that the thrust varies linearly with throttle percent (and ignoring that they normally only throttled to 67%) gives the expected approximate 3 g's
Info on nominal throttle settings in the answer to this question: Which STS mission raised the normal engine throttle above 100%, and what change to the SSME made that possible?