Resumen de An Instructive Apparatus for Determining the Density of Liquids Based on Archimedes’ Principle
Jr. Salmon Landi, Alexandre Divino de Souza, Thiago Milograno de Carvalho
Density is an important property in various fields; for example, it is used in the quality control of chemical and food products, and in the determination of the alcohol content in beers. In medicine, an anomalous urine density may indicate certain diseases, or an anomalous blood density, anemia. Among the most modern instruments for determining the density of liquids, the vibrating-tube densimeter is the most widely used, mainly in the petroleum industry.1 In this paper, we propose an experimental activity, which is appropriate for high school and first-year university physics students, in which the density of various liquids, such as saturated aqueous NaCl, tap water, soy oil, or 70% alcohol, is determined. The apparatus required for the experiment is an acrylic box, a syringe, four coins, and water, and the students should be familiar with Archimedes’ principle and graphical analysis. The values obtained for the density of liquids differ by a maximum of 2.3% from the accepted values (or “expected values”), indicating that the activity proposed is appropriate to encourage students to explore data that they measure themselves
