The Difference between Weight Ounces and Fluid Ounces

Refer to Table 1.3, which lists conversions between U.S. common volumetric measurements. Notice that there are 16 ounces in a pint (2 cups). Recall that there are 16 ounces in a pound. Why, then, did we see from Table 1.2 that a pint does not weigh 1 pound for all ingredients? Likewise, how can there be 16 tablespoons in a cup and 8 ounces in a cup, but 16 tablespoons does not necessarily weigh 8 ounces? These are the problems that result when one word—ounce—is used to represent two different concepts.