Transcript Sea Gulls

Chapter 2.6
What is density?
Density
Density is a measure of how tightly
matter is packed into a given volume
Which box has more density?
1st box has more density
Which box has more density?
RED BOX
Formula for Density
To calculate density, we use the
formula
Density = mass
volume
EXAMPLE
Suppose you know the mass of an
object is 30 g and the volume is 15
cm3.
Density = mass/volume
Density = 30g/15 cm3
Density = 2g/cm3
Density Continued
Density is a property that can be used to identify an
object.
For example…
• gold = 19.3 g/cm3
• mercury = 13.6 g/cm3
• lead = 11.3 g/cm3
• silver = 10.5 g/cm3
• aluminum = 2.7 g/cm3
• rubber = 1.1 g/cm3
• water = 1.0 g/cm3
• cork = 0.24 g/cm3
• air = 0.0013 g/cm3
Sink or Float???
• Matter that has a greater density that
water will sink in water.
• Matter with a density lower than of
water will float.
Coke vs. diet coke experiment
• Which coke will float and which will
sink??? Tell me your prediction.
Did you know???
Most people can float because their
density is slightly less than that of water.
Self Check- page 44
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What is density?
Which would have more matter – a 1-cm cube of
lead or a 1-cm cube of rubber?
Suppose you have a metal bar. It’s mass is 57.9 g
and it’s volume is 3 cm3. What is it’s density?
If you cut the metal bar from question 3 in half,
what would the density of each half be?
What is the metal whose density you calculated in
question 3?
If you put a piece of cork in a container of water,
would it sink or float? Why? Hint - Use the table
on the recent slide to help answer the question.