Transcript Document

What is density?
Density is a comparison of how much matter
there is in a certain amount of space.
Which one is more dense?
Now which one is more dense?
What is density?
The amount of mass in a given volume.
The Formula For Density
• Density = mass OR
volume
mass ÷ volume.
Units for density: g
cm3
Why are these the units for density?
ALWAYS
REMEMBER
UNITS!
Let’s try a density problem together.
Frank has a paper clip. It has a mass of 9g and
a volume of 3cm3. What is its density?
On your table try and find the density.
•Density = mass
volume
OR
mass ÷ volume.
Frank has a paper clip. It has a mass of 9g and
a volume of 3cm3. What is its density?
•Density = mass OR
mass ÷ volume.
volume
Density = 9g ÷ 3cm3 = 3g/cm3
Frank also has an eraser. It has a
mass of 3g and a volume of 1cm3.
What is its density?
•Density = mass OR mass ÷ volume.
volume
Answer
Frank also has an eraser. It has a mass of 3g
and a volume of 1cm3. What is its density?
•Density = mass OR
volume
3 ÷ 1=3g/cm3
mass ÷ volume.
Work on these problems with your
neighbor.
1.) Jack has a rock. The rock has a mass of 6g
and a volume of 3cm3. What is the density of
the rock?
2.) Jill has a gel pen. The gel pen has a mass of
8g and a volume of 2cm3. What is the density
of the rock?
Answer 1.
Jack has a rock. The rock has a mass of 6g and a
volume of 3cm3. What is the density of the rock?
•Density = mass OR
volume
6 ÷ 3= 2g/cm3
mass ÷ volume.
Answer 2.
Jill has a gel pen. The gel pen has a mass of 8g
and a volume of 2cm3. What is the density of
the rock?
•Density = mass OR
volume
8 ÷ 2=4g/cm3
mass ÷ volume.
Now, try these on your own.
3.) Al’Licia has a watch. It has a mass of 4g and
a volume of 2cm3. What is the density of the
watch?
4.) Mia has a wallet. It has a mass of 15g and a
volume of 5cm3. What is the density of the
wallet?
Answers
3.
4.
•mass ÷ volume.
•mass ÷ volume.
4 ÷ 2=2g/cm3
15 ÷ 5=3g/cm3
Liquid Layers
• Check out this picture. Which layer
has the highest density?
• Which layer has the lowest density?
• Imagine that the liquids have the
following densities:
– 10g/cm3.
– 6g/cm3.
3g/cm3.
5g/cm3.
• Which number would go with which
layer?
3g/cm3
5g/cm3
6g/cm3
10g/cm3
Liquid Layers – Try with your
neighbor
• Which liquid has the
highest density?
• Which liquid has the
lowest density?
• Which liquid has the
middle density?
•Which liquid has the
highest density?
Golden Syrup
•Which liquid has the
lowest density?
Oil
•Which liquid has the
middle density?
Water
Measuring the Volume by
Displacement of Water
1. Take the initial reading (without the object).
2. Place the object in the cylinder.
3. Take the final reading.
4. Subtract the the original amount from the final amount.
Mistakes
Try this with your partner.
1. Take the initial reading
(without the object).
2. Place the object in the
cylinder.
3. Take the final reading.
4. Subtract the the original
amount from the final
amount.
Original volume = 200 cm3
Final volume = 260 cm3
260cm3 - 200 cm3 = 60 cm3
Object volume = 60 cm3
What is the volume of the Toy Dinosaur?
Original volume = 4.8 cm3
Final volume = 5.6 cm3
5.6cm3 – 4.8 cm3 =.8 cm3
Object volume = .8 cm3