Which weighs morelead or cork

1
Which weighs morelead or cork?
2
Many people would answer ________.

• People assume that the question refers to equal
  volumes of lead and cork.
• A block of lead would weigh more than a block of
  cork.

3
Which weighs morelead or cork?

• As the question is presented, there is no correct
  answer.
• The question itself does not recognize the
  necessity of additional information to make it
  meaningful.

4

• In order to make comparisons clearer, scientists
  use the term DENSITY.
• DENSITY is defined as mass per unit of volume.
• Density mass
• volume

5

• Mass is measured in grams (g).
• Volume is measured in millileter (ml) or
• cubic centimeter (cc) or (cm3)
• 1 ml 1 cm3 1 g (water)

6
Example

• A piece of pure lead has a mass of 70 grams. Its
  volume is 6.2 cm3. To find density
• Density mass/volume
• Density 70 g/ 6.2 cm3
• Density 11.3 g/cm3
• All lead has a density of 11.3 g/cm3

7
Density mass/volume

• To find mass you use a ______, the units are
  ______.
• To find volume you use a _____ if it is a regular
  object to find volume of an irregular object you
  use a ______ ______.

8
What is the density of water?

• 1000 ml of water in a graduated cylinder has a
  mass of 1035 grams. The graduated cylinder has a
  mass of 36 grams. What is the mass of water?

9
Determine the density of

• A 2.2 cm by 4.4 cm by 4.1 cm rectangular solid
  whose mass is 20.5 grams.
• An object has a mass of 24 grams and is immersed
  in 15 cm3 of water. The total volume of the
  water and the object is 27 cm3. (What is the
  density?)

10
Density list

• Aluminum 2.7 g/cm3
• Copper 8.9 g/cm3
• Cork .24 g/cm3
• Corn oil .92 g/cm3
• Gasoline .66 g/cm3
• Gold 19.3 g/cm3
• Lead 11.3 g/cm3
• Mercury 13.6 g/cm3
• Nickel 8.9 g/cm3

• Silver 10.5 g/cm3
• Zinc 7.1 g/cm3
• Brass 8.0 g/cm3
• Steel 7.6 g/cm3
• Ice .92 g/cm3
• Tin 7.3 g/cm3

11
Equations

• Density Mass/Volume (units g/cm3 or g/ml)
• Mass Density x Volume (units g)
• Volume Mass/Density (cm3 or ml)

12
Look at the list of densities and determine
which objects will float in water.