This question was presented as one of those "think about it" questions in my physics class. Its not worth any points, but its driving me crazy! I can't figure it out. Here it is: Consider a pineapple sitting on a sensitive scale resting on the bottom of a large glass jar which is connected to a vacuum pump. The reading on the scale is 2.315 pounds with air in the jar. The air is now pumped out of the jar. Which of the following gives the best description of what happens to the scale reading and why. (a) The scale reading increases slightly because the buoyant force of the air is now gone. (b) The scale reading decreases slightly because the air used to be pushing down on the pineapple, but now it isn’t anymore. (c) Weight is caused by gravity and doesn’t have anything to do with the air, so the reading stays the same. (d) The reading decreases slightly because the scale reading used to include the weight of the air in the jar, but now the air is gone.