What is the same about these objects?

Density

What is the same about these objects?

Answer: These bottles all have the same volume.

Volume= Amount of Space and object takes up

What is different about these objects?

Answer: They contain

different samples of matter (cotton balls, water, iron filings, and air.)

Mass= Amount of Matter in an object

What is Density?

Density is the amount of matter in a given space

Which of the bottles is the MOST DENSE?

Example

Bobby Bobby

Bobby takes a trip to Florida. Compare his suitcase before his flight and after his flight.

Bobby’s Suitcase

• Imagine these boxes represent Bobby’s suitcase.

• Which would represent Bobby’s suitcase before his flight?

• Which would represent his suitcase after his flight?

Which is More

Dense?

Which one is more dense?

• Demonstration: People in a square

• How about this: Which square is more dense?

A B

Formula for Density

We use the formula:

Density = mass/Volume

OR

Density =mass

Volume

Liquid Layers

• Which layer has the highest density?

• Which layer has the lowest density?

• Imagine that the liquids have the following densities: 10g/cm3. 3g/cm3. 6g/cm3. 5g/cm3.

• Which number would go with which layer?

4. The DENSITY formula can be remembered using this

trick:

Inside the T-Triangle add the three letters from the Density formula. D = m/V

Think:

but put a D in place of the T.

m

D V

6. Let’s solve a problem using the DENSITY T-Triangle!

Example #1.What is the density of an object with a mass

of 50 g and a volume of 100 cm3?

What is the formulafor Density?

m

D V

6. Here’s how you solve the problem.

Example #1.What is the density of an object with a mass of 50 g and a volume of 100 cm3?

Formula Substitute Solve

(1) D = m/V (2) D = 50 g / 100 cm3 (3) D = 0.5 g/cm3

7. Let’s solve another problem using the DENSITY T-

Triangle!

Example #2.What is the mass of an object with a density of 1.2 g/mL and a volume of 0.3 mL?

What is the formulafor mass?

m

D V

7. Here’s how you solve the problem.

Example #2. What is the mass of an object with a density of 1.2 g/mL and a volume of 0.3 mL?

Formula Substitute Solve

(1) m = DV (2) m = 1.2 g/mL X 0.3 mL (3) m = 0.36 g

Notice: The like terms (mL) were cancelledso only “g” was left for the answer!

8. Let’s solve another problem using the DENSITY T-

Triangle!

Example #3.What is the volume of an object with a density of 3 g/cm3 and a mass of 30 g?

What is the formulafor volume?

m

D V

8. Here’s how you solve the problem.

Example #3.What is the volume of an object with a density of 3 g/cm3 and a mass of 30 g?

Formula Substitute Solve (1) V = m/D (2) V = 30 g X 3 g/cm3 (3) V = 10 cm3

Notice: The like terms (g) were cancelledso only “cm3” was left for the answer!

10. Solve these problems.

Example #4: What is the mass of an object with a density of 5 g/cm3 and a volume of 15 mL?

Example #5: What is the density of an object with a mass of 300 g and a volume of 30 mL?

Example #6: What is the volume of an object with a mass of

25 g and a density of 5 g/mL?