DenistyLuke Lyons

September 16, 2008Mrs. Nitteberg

Density is the Ratio of Mass to Volume

The density of an object is the mass of the object divided by volume of the object.

volume

massdensity

v

mD

Why do objects that are the same size sometimes have different weights? The answer has to do with their density. An object’s density is determined by comparing it’s mass to it’s volume. If you compare a rock and a cork that are the same size (equal volume) which is heavier? The rock! It is heavier, has more mass in the same volume.

Density of solids:To show the density of an object, we will

conduct an experiment:We need:

4 small objects (2 expected to float, 2 expected to sink)

Sheet of paper to record results Water Scale Measuring cup

Experiment #1Density of an object

Place each object in a bowl of water. Which ones float? Which sink? Record

your results Weigh each object. This gives you the

mass Observe the water level in the

measuring cup, then submerge each object. Record the new water level.

Subtract the starting water level from the final value. Now you have the volume

To calculate the density: Divide the volume by the mass.

Experiment #1

Results

Here are the results of our first experiment: Item 1: Penny Sink/Float-Sink

Density? Item 2: Clothespin

Sink/Float-Float Density?

Item 3: Car Sink/Float-Sink

Density? Item 4: Ball

Sink/Float-Float Density?

Experiment #2Density of Liquid

Measuring cup Water Corn syrup Vegetable oil Food coloring

Which liquid is more dense?

Carefully measure the exact amount of each liquid into separate containers.

Placing a few drops of food coloring into the water to tell it apart from the other liquids.

Pour each into a measuring cup. Let them settle.

Which liquid is at the bottom of the cup? Which is at the top?

Experiment #2

Even though each item poured was liquid the density of each caused them to separate.

The End