DENSITY

WHAT IS DENSITY? Density is defined as the mass per unit volume. Density is defined as the mass per unit volume. In other words, its how much matter is stuffed into a certain amount of space. In other words, its how much matter is stuffed into a certain amount of space. For example, take a golf ball and a ping pong ball. They are both about the same size. Which means that they take up the same amount of space or have the same volume. However, the golf ball has more stuff in it, therefore, it is more dense than the ping pong ball. For example, take a golf ball and a ping pong ball. They are both about the same size. Which means that they take up the same amount of space or have the same volume. However, the golf ball has more stuff in it, therefore, it is more dense than the ping pong ball.

The Formula The formula for calculating density is D=m/V The formula for calculating density is D=m/V The “D” stands for Density (of course). The “D” stands for Density (of course). The “m” stands for mass which is measured in grams (g). The “m” stands for mass which is measured in grams (g). The “V” stands for volume which is measured in cubic centimeters (cm 3 ) or milliliters (mL). The “V” stands for volume which is measured in cubic centimeters (cm 3 ) or milliliters (mL). The “/” means divided by. The “/” means divided by. Therefore, Density equals mass divided by volume and its units are g/cm 3. Therefore, Density equals mass divided by volume and its units are g/cm 3.

Check it Out! On the front table, you see a plastic bin filled with water. On the front table, you see a plastic bin filled with water. Water has a density of 1 g/cm 3. Water has a density of 1 g/cm 3. For something to float in water, it has to have a density less than that of water. For something to float in water, it has to have a density less than that of water. When something sinks in water, it has a density that is greater than water. When something sinks in water, it has a density that is greater than water. On your paper, predict whether the objects will sink or float. On your paper, predict whether the objects will sink or float.

Predict Now, let’s CHECK IT OUT! Now, let’s CHECK IT OUT!

NOW…. Will COKE or DIET COKE float in water? Will COKE or DIET COKE float in water? In the Venn Diagram on your paper, list the similarities and differences between Coke and Diet Coke. In the Venn Diagram on your paper, list the similarities and differences between Coke and Diet Coke.

VS Different Main ideas Similar Different COKEDIET COKE Shape Size Color Weight Ingredients Other are made by the same company have the same shape made of aluminum are sealed shut have the same amount of liquid - 12 fl oz contain water contain carbon dioxide both have caffeine Red can Regular (not diet) Contains sugarContains nutra sweet Silver can Diet soda

So…. Will COKE or DIET COKE float in water? Will COKE or DIET COKE float in water? Let’s check it out. Let’s check it out. The Coke sank and the Diet Coke floated. The Coke sank and the Diet Coke floated. WHY? WHY?

Because…. Coke contains about 39g of sugar. Coke contains about 39g of sugar. Diet Coke contains about 0.1g of aspertame (NutraSweet). Diet Coke contains about 0.1g of aspertame (NutraSweet). Therefore, Coke is more dense than Diet Coke and more dense than water, so it sinks and Diet Coke doesn’t. Therefore, Coke is more dense than Diet Coke and more dense than water, so it sinks and Diet Coke doesn’t.

Practice Calculating Density Using the formula for density, D=m/V, calculate the density of an object that has a mass of 35 g and a volume of 7 cm 3. Using the formula for density, D=m/V, calculate the density of an object that has a mass of 35 g and a volume of 7 cm 3. Will this object float in water or sink? Will this object float in water or sink?

The End Turn your papers in as you leave. Turn your papers in as you leave. Make sure that your name is on your paper. Make sure that your name is on your paper. Have a nice day! Have a nice day!

Leigh Miller, Pillans MS