# Archimedes Principle Name

 Date conversion 19.08.2017 Size 27.85 Kb.

Archimedes Principle Name _________________

## Materials

two 20gram slotted masses

600 ml beakers & 2oz Solo Cups (about 60mL size cup)

Triple beam balance

Density Set (e.g. aluminum, brass, steel, lead)

50 ml graduated cylinder & Spill Cup

Support structure for triple beam balance for weighing hanging objects

## Introduction

The story is told that the Greek mathematician Archimedes liked to lounge around in his bath all day. He would work out his geometric proofs on his stomach (he was quite fat) writing with bath oil. One day when he was contemplating why things floated, the idea, which has become known as Archimedes' Principle, occurred to him. He became so excited by his discovery that he jumped out of his bath and ran through the streets of his town shouting "Eureka" which is Greek for "I've found it". In this lab we will attempt to grasp some of Archimedes' excitement by rediscovering his principle.
Part 1 Discovery Activity

Procedure

a) Put both 20 gram masses in the 2oz cup. Fill the spill-cup as shown by your instructor. Measure the overflow when the cup is softly placed into the spill-cup.
Water displaced by floating cup with masses inside it: ____________mL.

b) Re-fill the spill-cup as before. Prepare to measure overflow. Next, gently float the empty 2oz cup and then gently drop both 20 gram masses directly into the water.

Water displaced by sunk masses and the floating cup: ____________mL.

Part 2 Determining Archimedesâ€™ Principle

Safety : No eating or drinking in the lab while performing this procedure. Wash hands after handling the lead.
The Density Cube Set consists of the following materials

• aluminum (light grey color, least dense)

• brass (shiny copper color)

• steel (grey color, sharp edges)

• lead (grey color, soft edges)

## Procedure

1. Weigh each of your objects in air and record in Column M1.

2. Weigh each of your objects while completely submerged in water and record in Column M2.

3. Fill the spill cup with water. Slowly lower the first object into the water, collecting the overflow in the cylinder. Record the displaced mass in Column B noting that *1mL of water has a mass of 1 gram. Repeat for all objects.

 M1 M2 A B Mass in Air Mass In Water M1 â€“ M2 Mass of Displaced Water* (grams) (grams) (grams) (grams) aluminum brass steel lead

Calculate the density of each object in grams/cm3 , by dividing the mass in air by the volume of displaced water (note that 1mL = 1cm3).

 E A Experimental Density (g/cm3) Reference Density (g/cm3) Aluminum 2.70 Brass 8.50 Steel 7.85 Lead 11.34

Summing Up

1. A boat is floating in water. What will cause the water level to rise more?

a) A chunk of metal is put in the boat.

b) The same chunk of metal is thrown into the water.

2. A block of steel is suspended in water by a string. What forces act on the block?

b) Buoyant-force of water on block

c) Tension force of the string pulling up on block

d) All of the above

3. When a piece of steel is suspended in water by a string, which of the forces acting on it is the largest in size?

a) Weight of the steel

b) Buoyant force on the steel

c) Tension force of the string that is holding the steel up

d) All of these forces have the same magnitude

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