1. Cartesian Divers!

2. List 5 facts or observations!
Cartesian Divers!
How do they work?
List 5 facts or observations!
Sketch a diagram

3. When is it easier to make the divers sink?
When the bottle has very little air in it.
When the bottle is half-full of air. A B

4. Can you change the density of water by pushing on it?
Is Water Compressible?
Can you change the density of water by pushing on it?

5. Can you change the density of air by pushing on it?
Is Air Compressible?
Can you change the density of air by pushing on it?

6. No. Only air is compressible. The density of air can change.
Is Water Compressible?
No. Only air is compressible. The density of air can change.

7. Using density, explain why the diver floats.
Water’s density = 1 g/cm3. The diver’s density is less than 1 g/cm3.
0.5 g/cm3
1 g/cm3

8. Density = =
= 0.5 g/cm3
10 g
20 cm3
As compared to water, 0.5 g/cm3 is less dense than water. It floats.

9. What changes when you squeeze the bottle? (Don’t say color.)
Volume Changes.

10. Volume Changes due to increased pressure.

11. Density = Mass/Volume Mass = 10 g Volume = 20 cm3 Volume = 5 cm3
Density = 0.5 g/cm3
Density = 2 g/cm3

12. When volume decreases,
Density…
2 g/cm3
Increases!

13. Is the mass of the diver changed at all?
No! Mass does not change.
Volume decreases and density increases.
1 g/cm3
2 g/cm3

14. Using density, explain why the diver sinks.
Water’s density = 1 g/cm3.
The diver’s density is greater than 1 g/cm3.
1 g/cm3
2 g/cm3

15. Which diver will sink first?
Predict
Which diver will sink first? A B

16. Which diver will rise first?
Predict
Which diver will rise first? A B

18. Review
Mass
Volume
Density =

19. 1. Why does a cube of ice float in water?
Review
1. Why does a cube of ice float in water?

20. Water versus Ice
Water

21. Question 1
Three cubes have the same volume, but very different densities. Which cube has the greatest density?
2 g
10 g
20 g

22. Question 2
Three cylinders have the same volume, but very different densities. Which cylinder will displace the most water when submerged? Or will each cylinder displace the same volume of water?
Same
8 g
12 g
32 g

23. Review
Which is denser?
Both boxes have the same volume.

24. What is the density of the ship?
0.9 g/cm3

25. Which one is more likely to float in H2O?
Review
Which one is more likely to float in H2O?
Both boxes have the same volume.