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?