PROCEDURE

A laboratory balance was fitted with a stationary platform, and used to compare the weights of dry objects with their submerged weights. Measurements of mass and apparent mass were read directly from the dry and submerged weights, respectively.

Dry samples of cork, aluminum alloy, and yellow brass were weighed on the balance pan in normal fashion. To obtain submerged weight, the samples were dangled from the balance arm using thin nylon string, and submerged in a beaker of tap water resting on the stationary arm.

Submerging the sample of cork, whose density is less than that of water, required use of a metal sinker attached to the cork by a short length of string. The entire assembly was dangled from the balance arm, and weights were obtained for (1) sinker portion submerged, and (2) sinker and cork both submerged. Apparent mass of the sinker alone was then subtracted from apparent mass of sinker plus cork, to give apparent mass of the cork.