Experimental Method to Determine Some Physical Properties in Physics Classes

Luiz Fernando Pires,André Maurício Brinatti,Sérgio Da Costa Saab

doi:10.1590/01000683rbcs20140766

Luiz Fernando Pires, André Maurício Brinatti + Show 1 more

Open Access

https://doi.org/10.1590/01000683rbcs20140766

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Abstract

ABSTRACT Particle density, gravimetric and volumetric water contents and porosity are important basic concepts to characterize porous systems such as soils. This paper presents a proposal of an experimental method to measure these physical properties, applicable in experimental physics classes, in porous media samples consisting of spheres with the same diameter (monodisperse medium) and with different diameters (polydisperse medium). Soil samples are not used given the difficulty of working with this porous medium in laboratories dedicated to teaching basic experimental physics. The paper describes the method to be followed and results of two case studies, one in monodisperse medium and the other in polydisperse medium. The particle density results were very close to theoretical values for lead spheres, whose relative deviation (RD) was -2.9 % and +0.1 % RD for the iron spheres. The RD of porosity was also low: -3.6 % for lead spheres and -1.2 % for iron spheres, in the comparison of procedures – using particle and porous medium densities and saturated volumetric water content – and monodisperse and polydisperse media.

Highlights

Porosity (φ) is an important property of porous media
The density of porous systems is defined in two ways: particle density and porous medium density (Reichardt and Timm, 2004; Prevedello and Armindo, 2015)
When the porous medium soil is considered, which consists of three phases, particle density is called solid density and porous medium density is known as soil bulk density (d)

Summary

Introduction

Porosity (φ) is an important property of porous media. In physics, φ is defined as the ratio of the pore volume of the porous medium by the respective total volume. One alternative is to simulate porous media and obtain its physical properties, such as: particle density, porous medium density, gravimetric and volumetric water contents, and porosity.

Results

Conclusion