1. Unit 3 INTRO Calculating Density

2. Tuesday, November 8
Using scientific vocabulary, try your best to explain what is happening in this photograph.

3. What makes it happen?
Beginning course details and/or books/materials needed for a class/project.

4. DENSITY
Density is defined as mass per unit volume. It is a measure of how tightly packed and how heavy the molecules are in an object. Density is the amount of matter within a certain volume.

5. Density Formula Density is mass divided by volume.
Density = mass/volume
The unit for mass is grams
The unit for volume is mL or cm3
The unit for density is…
g/mL or g/ cm3

6. Units for density g/cm3 or g/ml
Formula:
M = mass V= volume D = density
M = D x V V = M / D D = M / V

7. Answer the following question, using the magic triangle.
What is the mass of an object if the density is 25 g/mL and the volume is 5 mL?

8. Answer the following using the correct units.
What is the volume of an object if the density is 75 g/mL and the mass is 125 g?

9. Density is the Mass per unit Volume
What is Density?
If you take the same volume of different substances, then they will weigh different amounts.
Wood
Water
Iron
1 cm3
1 cm3
1 cm3
IRON
0.50 g
1.00 g
8.00 g
Q) Which has the greatest mass and therefore the most dense?
Density is the Mass per unit Volume

10. Water and Density Since 1-gram of water has a volume of 1-mL
then the density of water =1 gram/mL.
5o-mL of water will have a mass of 50 grams
so again the density of water =1 g/mL.
A kg of water will have a volume of mL
so again the density of water =1 gram/mL.

11. Objects that Sink
Objects with a density greater than 1 g/mL will sink in water.

12. Neutral Buoyancy
Objects with a density equal to the density of water will float in mid water, at what ever level you place the object.
Fish and submarines control their depth by changing their density.

14. DENSITY g/cm3 Aluminium 2.70 Iron 7.86 Brass 8.50 Wood 0.50 Slate 2.80
Glass
2.50
Lead
11.3
Marble
2.70
Wax
0.89

15. Density! In liquids… Things that are more dense sink to the bottom
Things that are less dense rise to the top
A schedule design for optional periods of time/objectives.

16. Which is more dense?
Inference:
Evidence:

17. Which is least dense?
Evidence:
Inference

18. Which LIQUID is more dense?
Evidence
Inference

19. What the heck is density?
Density is the amount of matter packed into a certain space.
Less dense
Introductory notes.
More dense

20. What the heck is density?
Density is the mass of a substance divided by the volume of the substance.
Density = mass/volume
A list of procedures and steps, or a lecture slide with media.

21. I LOVE DENSITY!

22. Need to make two measurements
Mass
The amount of matter in a substance
Kinda like how much it weighs
Volume
The amount of space a substance takes up
Kinda like how big it is

23. Need to make two measurements
Mass
Measure with a triple beam balance
Volume
Measure with a centimeter ruler

24. But How… Mass Start with sleds at 0 100 grams? 10 grams? 1 gram?
Volume
Little lines are 0.1 cm
Measure length
Measure width
Measure height
Volume = l x w x h

25. Practice Reading

26. Density units Mass Measure in grams Volume
Measure in centimeters 3 times
cm3

27. Another way to measure volume
If you’ve got stuff that is not a cube…
Put some water in a graduated cylinder
Make note of the amount of water
Drop in “the thing”
Note the new water level
Subtract

28. Metrics is so cool!
cm3 = ml

29. How to calculate Density