Student Guide for Density Simulation Name: _______________Partner:_____________ Block:___
(note: “sink” means stays on the bottom)
Start: 1.
Google: “Phet Density sim” and click on the first link OR go to my blog
OR go to http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
2.
Click on the
button
3.
Experiment with choosing a material:
material
List the materials in the boxes
Try to get aluminum to float.
Talk
S=sink
F=Float
Density given
Styrofoam
F
0.15 kg/L
Wood
F
0.4 kg/L kg/L
Ice
F
0.92 kg/L
Brick
S
2 kg/L
Aluminum
S
2.7 kg/L
with your partner about this possibility- can you change the mass of the aluminum block without
changing the volume of the aluminum block?
Circle one YES/ NO
5. Look at the density triangle at the bottom of the box- Why do you think this does or does
not move?
Mass and volume change together (proportionally) so density stays the same for
aluminum
6. How does the density of aluminum (2.70 kg/L) help explain what you see?
The aluminum will sink in the water because the density of the aluminum is 2.7kg/L and the
density of water is 1 kg/L. We have learned that if something is more dense than
water, it will sink
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7.
Density = ----------
“ mass over volume equals density
8. Calculating Density. In the “Blocks” box, click on Mystery
Test the boxes in the water- just drag into the water and let go!!!
:
Object
Sink or
Float?
Mass
(kg)
Volume
(L)
Density
(kg/L)
A
B
C
D
E
Identification
(hint: use Show Table for
help)
Gold
Apple
Gasoline
Ice
diamond
9.
Look closely at green box C and red box D and discuss your observations with your partner.
List three observations you made while comparing the two boxes.
1st observation
2nd observation
3rd observation
C Bigger size
C Bigger mass
D Bigger density
D floats lower than C
10. Write these labels above the density scale where you think they fit best:
Floats well
Barely sinks:
floats better
than it sinks
Low Density
Water
0
0.5
1
Barely floats:
sinks better than
it floats
Sinks quickly
High Density
1.5
2
Density (kg/L)
2
2.5
3
3.5
Part 2. Exploring different materials and different sizes.
11. In your own words, what you think the label “Volume” means? amount of space an object takes up
12. what you think the label “Mass” means? Amount of matter in an object
13. Design your own block! In the “Blocks” box, click on Custom. Experiment with making your own block out
of your own material with “My Object”.
a) What properties of the block can you change?
Mass and volume
b) What makes a block more likely to sink? How does this change the block’s density?
High mass and low volume  high density
c) What makes a block more likely to float? How does this change the block’s density?
low mass and high volume  low density
14. Try to create a block with a very HIGH density.
Do you think your blockwill sink or float? ______sink_______
What is your block’s volume? _______1 L________What is your block’s mass? _________10 kg______
15. Try to create a block with a very LOW density.
Do you think your blockwill sink or float? _____float________
What is your block’s volume? _______10 L___What is your block’s mass? _______1 kg_________
16. Your friend has three blocks (A, B, and C) of the SAME SIZE, but they each float differently in water.
A
C
B
What do you think is making them float differently? Different densities because more mass in same space
makes particles closer together (higher density)
17. Using “My Object”, check your answer by playing with your block to make it behave like A, then B, then C.
a. Which slider did you need to change?_________mass______________
b. Could A, B, and C be made out of the same material? Why or why not?
no, different densities means they have to be different materials because if you have the same volume, you
can’t have the same material have different masses (mass and volume need to change proportionally)
c. Which object must have the most mass? __B___
d. Which has the second most mass? ___C____
e. Which has the least amount of mass?___A_____
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18. Test your ideas using the objects of “same volume”.
a. All of these blocks have a volume of ____5____ L .
b. Besides being different colors, the blocks also have different masses
c. Observe how they float. What do you notice? The light boxes float more than the heavy ones
d. If all of the blocks have the same volume, why do you think some are floating and some sinking? Since the
volume is the same for all boxes, the boxes with more mass have more particles in the same amount of
space so the particles have to be closer together = more dense = sink
19. Explore objects of the “same mass”.
a. All of the blocks have a mass of ______5___ kg.
b. All of the blocks are different colors and different volumes
c. Observe how they float. What do you notice? the big boxes float more than the small boxes
d. If all of the blocks have the same mass, why do you think some are floating and some sinking?
Since the mass is the same the number of particles is the same so the bigger boxes (higher volume) have
more space for the particles to spread out = less dense = float
AND the smaller boxes (lower volume) have less space for the particles so they have to be closer together =
more dense = sink
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