Experimental physics laboratory 2: calculating the value of water density using metal rod and water container

This article presents a detailed analysis of an undergraduate physics laboratory experiment designed to determine the density of water using fundamental measurement techniques and data analysis methods. The experimental setup consists of a precision scale, a graduated container filled with water, and a suspended metal rod held by a crank, allowing for controlled displacement measurements. The primary objective of this experiment is to reinforce essential concepts in experimental physics, particularly in deriving physical models that correlate measurable quantities, performing precise measurements, and analyzing data using regression techniques via ordinary least squares methods for fitting data into linear models. This article aims to provide students with a theoretical and computational aid to explore the physical interpretations of this experiment. A theoretical framework is derived to introduce fundamental concepts of hydrostatics, Newtonian mechanics, and the main equations used in the experiment. Python codes that perform analysis on the experiment are supplied with thorough explanations.