Homer is not God, thus is not infallible...remember in his time, he did not have microsoft XP to do his publishing...
Not a valid excuse since, for whatever reason, it has not been corrected in the 7th edition.
How can one confuse the concept of impulse and acceleration. Such an un-Homer thing to do.
Still awaiting for a good reason, maybe Yoda? I remember Yoda saying that there are no factual errors in The Golfing Machine (although certain concepts may be expressed a lot more clearly). If this isn't a factual error, then...