error on the key
There was an error on the key for the last homework- unfortunately, the grader did not pick up on it.
on 14.6, the book you have states that the area of a lid is 77m2. In the copy of the text I have at home (must be a different version) it states it as 77cm2, which makes a lot more sense for a lid of negligible weight. As you might imagine, this makes a great deal of difference to the answer. Since I'm guessing the grader took a point off of everyone's paper for an incorrect answer, I'm going to put one point back on everyone's HW12 (who turned it in), to save the trouble of digging through all of the assignments again.
I will post an addendum to the key.
jay-