Microcomputer-Based Laboratory for Archimedes' Principle and Density of Liquids

Abstract

Archimedes' principle is one of the fundamental themes of the mechanics of fluids in high school; it is described in detail in any introductory physics textbook1 and it asserts that “a body immersed, or partially immersed, in a fluid receives an upward force equal to the weight of the fluid it displaces.” In mathematical terms, Fup = ρgVx, where ρ is the fluid density, g the free-fall acceleration, and Vx the volume of the immersed portion of the body. In a partially immersed body, the fluid exerts pressure on all surfaces of the body, laterally and on the bottom [Fig. 1(a)]. Notice that the forces on the sides cancel by symmetry and the net effect of the fluid pressure is an upward buoyant force. Likewise, if the body is totally immersed [Fig. 1(b)], the fluid also exerts pressure on the top of the body, but since the pressure on the bottom will be greater than on the top (pressure increases linearly with depth in a fluid of uniform density), the result is a net upward buoyant force.

Archimedes’ principle experimental apparatus for remote physics laboratory

“…Figure 7 displays the apparatus used in the Archimedes' principle experiment, including all associated hardware. The novelty of this study, when compared to the research [6], lies in the computerization of hardware control systems. The stepper motor is computerized and controlled to immerse the object into the liquid.…”

“…When an object is hung on a force sensor, and the object is in a state of static equilibrium, the Reprinted from [6], with the permission of AIP Publishing.…”

“…The buoyant force value is then obtained, which equals the weight of the liquid being moved. Gianino [6] developed an experimental method to determine fluid density using a microcomputer-based laboratory (MBL), which consists of a force sensor, computer, and data acquisition system for better results. In this case, the load is hung on the force sensor.…”

Favoriser la compréhension des concepts du mouvement rectiligne à vitesse constante à l’aide d’une investigation scientifique assistée par ordinateur

“…Une telle démarche possède plusieurs avantages. Premièrement elle permet à l'élève de se concentrer sur l'élaboration d'hypothèses et l'interprétation des résultats, deux habiletés peu développées dans les laboratoires traditionnels (Gianino, 2008). Deuxièmement elle permet à l'élève de générer et de vérifier rapidement plusieurs hypothèses, en facilitant chez ce dernier les stratégies de variation des paramètres nécessaires à la formulation d'hypothèses à propos des propriétés des phénomènes (Riopel, 2005).…”

Effect Of A Video-Based Laboratory On The High School Pupils’ Understanding Of Constant Speed Motion

“…In this approach, called 'video-based laboratory' or VBL, the motion of objects are recorded as videos, treated by softwares allowing at the same time the measure of the positions of objects according to time and the organization of these data in tables and graphs. Such an approach has several advantages: 1) it allows the pupil to focus on the generation of hypotheses and the interpretation of results, two skills not much developed in traditional laboratories [10]; 2) it allows the pupil to generate and to prove several hypotheses much faster, by making easier strategies of variation of parameters necessary for the formulation of hypotheses regarding the properties of phenomena [11,12]; 3) in physical situations where it is necessary to come back on the results of an experience to check the accuracy of the results obtained or possibly to change the original hypothesis, VBL can allow the traditional laboratory to become iterative in spite of the school constraints with respect to time or equipment. In effect, it is often necessary for the pupil to come back on the results of an experience to study the reasons of the gap between his ideas and his experimental results, thus favoring conceptual change in sciences [13,14].…”