# Specific gravity by archimedes principle

As he waded into deeper water, the force on his feet became less. It has numerous applications, one of which is the determination of density and specific gravity. Density is the mass per unit volume of a substance. The metric system unit GRAM is defined to be the mass of one cubic centimeter one milliliter of pure water at 3. Archimedes' Principle Background Reading Science historians generally agree that the idea for his principle occurred to Archimedes as he entered a bath pool. As he waded into deeper water, the force on his feet became less. Archimedes' Principle is that an object totally or partially immersed in a fluid liquid or gas is buoyed lifted up by a force equal to the weight of the fluid that is displaced.

It has numerous applications, one of which is the determination of density and specific gravity. Density is the mass per unit volume of a substance.

The metric system unit GRAM is defined to be the mass of one cubic centimeter one milliliter of pure water at 3. The definitions given above suggest various methods for determining specific gravity.

For the third equality, the numerator and denominator were multiplied by "g". WS is the weight of the substance measured in air; WW is the weight of the water displaced by the substance when it is immersed.

In some circumstances, the volume of the substance is equal to the volume of the water. In particular, when a solid object is completely immersed in water, the volume of the water displaced must be equal to the volume of the object.

Furthermore, by Archimedes' Principle, upon immersion the object would receive a buoyant force equal to the weight of the water displaced. Thus, an object weighed in air and then weighed while immersed in water would have an effective weight that was reduced by the weight of the water displaced, if the buoyant force of the air is negligible.

When weighed in air, the object receives a buoyant force equal to the weight of the air displaced by the object. However, the density of air is small enough compared to the density of most solids to allow this buoyant force to be neglected when weighing most solids in air.

The SG would then be the weight in air divided by the apparent loss of weight when weighed in water. A device called a Jolly Balance is designed to measure the weight of objects in air and in water by reading the elongation of a spring.

It utilizes a Vernier scale to read the elongation of the spring to the nearest 0.

## Density and Buoyancy

If the object is less dense than water, a lead weight must be attached and three spring elongations must be measured to determine the SG.

The three elongations are xA: You should derive this formula in terms of xA, xB, and xC. Having determined the SG for sinking and floating objects using Archimedes' Principle and the Jolly Balance, it is desirable to use an independent method for comparison.

For a liquid The Volumetric Flask or Pycnometer has a hollow stem stopper that allows one to prepare equal volumes of fluids very reproducibly. If the mass of the flask is measured 1 when empty, 2 when filled with the fluid, and 3 when filled with water, the SG of the fluid can be determined.

Since the volume is the same, it will cancel out of the SG fraction.

## Density and Pressure

Procedure We will perform three separate experiments in which we will determine the density and specific gravity of a solid more dense than water a solid less dense than water a liquid Set up the Jolly Balance Level the Jolly balance using the screws on the legs so that the scribed rod does not touch the clear plastic sleeve.

Set the Vernier scale to zero 0. Move the clear plastic sleeve until the scribe line on it is aligned with the scribe line on the hanging metal rod. Part 1- an object more dense than water Measure the mass of the dense dark colored ball on a triple-beam balance.

Measure the diameter of the ball using a Vernier caliper several times. You decide how many. Choose many different orientations, not all in the same plane. Place the ball on the spring of the Jolly balance.

Turn the knob at the base until the scribe line on the metal rod is aligned with the scribe line on the plastic sleeve.(Specific gravity, however, does not have dimensions). Archimedes’ Principle (which is derivable from mechanics) states that a body immersed in a fluid is buoyed .

Jun 12,  · Buoyancy: Archimedes Principle SUBJECT: Physics TOPIC: Buoyancy DESCRIPTION: A set of mathematics problems dealing with buoyancy. CONTRIBUTED BY: Carol Hodanbosi EDITED BY: Jonathan G. Fairman - August There are two types of flying machines that allow for lift to overcome gravity. This principle can be used to find out the density (or the specific gravity) of a body made of a particular material.

## Specific Gravity and Archimedes Principle

Density: Density is ratio of the mass of a body to its volume. The Activity: The activity which deals with the Archimedes Principle includes objects made from ten different materials.

Archimedes’ Principle Goals • In this exercise, you will be studying Archimedes’ prin-ciple, speciﬁcally exploiting it to measure the speciﬁc gravity of a few diﬀerent solids. Apparatus • Triple-beam balance, two solid metal cylinders, piece of wood or cork, unknown liquid, vernier caliper. Buoyant Forces, Density, and Specific Gravity Preparation Prepare for this week's quiz by reading the sections of your textbook that cover Archimedes' Principle, buoyant forces, density, and specific gravity. Principles Density The density (ρ, pronounced "rho") of an object is . Lab: Archimedes Principle Updated 10/03/16 Part C (no uncertainty in the calculations) ***just be reasonable in significant digits • specific gravity from equation 3 (part C).

Archimedes' Principle