1. Jimmy does a cannonball into a swimming pool
Jimmy does a cannonball into a swimming pool. After surfacing and floating around for a few seconds he observes something interesting. He notices that if he takes a deep breath his body seems to float more. Also, he notices that if he breathes out, his body floats less, or he sinks into the water. Explain why this is happening to Jimmy.

2. Which object has a greater density?

3. Bowling Ball or Volley Ball?

4. Density is equal to the mass of an object divided by its volume.
D = M V
Density is equal to the mass of an object divided by its volume.

5. Think of an elevator: Less dense: one person in an elevator
More dense: twenty people crammed in an elevator

6. Density: Sample values: Gold 19.3 gm / cm3 Potato 1.6 gm / cm 3
Water 1 gm / ml
Corn oil 0.9 gm / ml

7. If an object is LESS dense than water it will FLOAT
If an object is MORE dense than water,
it will SINK
(The density of water is 1 gm / cm3)

8. Find the density of the object below.
The object was placed on a triple beam balance. 20
An object was dropped into a graduated cylinder that contained 40 mL. Determine the volume of that object.
5.4
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9. Volume = Volume of water & object – volume of water
The solution …
Volume = Volume of water & object – volume of water
V = 65 mL – 40 mL
V = 25 mL
M = 25.4 g
Density = Mass ÷ Volume
D = 25.4 g ÷ 25 mL
D = 1.01 g/mL
** The object will sink!

10. Consider this:
Justin has a block of pure gold the size of a chalk board eraser.
Eliza has a ring that is also pure gold
The mass of the gold block is obviously greater than the ring.
How does the density of the block compare to that of the ring?

11. Key Point:
Density does not depend on size – it is a property of a substance that remains the same!
Ex. A small gold ring has the same density as a large gold brick because they are both gold.

12. Your mission:
Using only the materials provided, the information below, and your brain, find the approximate density of the straw, penny and the grape.
Info:
Density of water 1 g / ml
Density of corn oil 0.9 g / ml
Density of corn syrup 1.5 g / ml