Experiment 7: Relative Density
Laboratory Report
Moses Joshua Montilla, Jared Paolo Nacino, Daryl Janus Panganiban, Matthew Allan Papa
Department of Sports Science
College of Rehabilitation Science, University of Santo Tomas
España, Manila Philippines
Abstract
The experiment about relative density is composed of three different activities. The first activity is about the Displacement Method for alloy, the second activity is about getting the density of a bone and the third activity is about Regular versus Diet Soft Drinks.
1. Introduction
Relative density is the ratio of the density (mass per unit volume) of a substance to the density of a given reference material. The theory or the principle that we used for the experiment is the Archimides’ Principle which states that any fluid a buoyant force to an object that is partially or completely immersed in it; the magnitude of the buoyant force equals the weight of the fluid that the object displaces. In the experiment we used different formulas. For activity 1 (g) mass of the substance which is Aluminum, (cc) initial level of water, (g/cc) for the experimental value, magnitude of buoyant force [pic]= Wfluid which is weight of displaced fluid. For activity 2 we used formulas for getting the relative density of the bone.
[pic]
[pic]
For experiment 3 we used formulas like
[pic]
2. Theory
Activity 1: Displacement Method for Alloy
The Aluminum bar was weighed and its mass was recorded. Some water was placed into a graduated cylinder and the initial water level was recorded. The Aluminum bar was placed inside the cylinder and the new water level was recorded. The volume of the Aluminum bar was computed by subtracting the initial water level from the resulting water level. The density of the Aluminum bar was computed by dividing its mass by its volume. The calculated density was compared to the standard density (2.7 g/cc) and the % error was taken.