C4.1: Density

1 / 19

# C4.1: Density - PowerPoint PPT Presentation

C4.1: Density. Physical Science. C4.1 Density. Supplies: A pencil and science notebook Standards: 8a) Density is mass per unit volume 8b) Calculate the density of substances from measurements of mass and volume 9f) Apply simple mathematic relationships to determine a missing quantity.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'C4.1: Density' - leala

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### C4.1: Density

Physical Science

C4.1 Density
• Supplies: A pencil and science notebook
• Standards:
• 8a) Density is mass per unit volume
• 8b) Calculate the density of substances from measurements of mass and volume
• 9f) Apply simple mathematic relationships to determine a missing quantity
C4.1 Density
• You will be taking notes using Cornell Notes format or Charting Notes format.
C4.1 Density
• Definitions
• Density: the mass of matter per unit volume; density is typically expressed in units of grams per milliliter (g/mL), grams per cubic centimeter (g/cm3), or kilograms per cubic meter (kg/m3).
Density is a property of matter
• Population density?
• Forest density?
• Density of stars?
• Air quality?
Density in Physics
• Density is a property of matter, like color or size.
• Density is mass per unit volume.
• Given a cubic centimeter of
• Steel
• Water
• Air
• Which has more mass?
Units of density
• Units are g/cm3
• Ratio means
• 1 g/cm3 = 1000 kg/m3
• Steel at 8.7 g/cm3 is 8,700 kg/m3 (multiply by 1000 and change units.)
• Oak at 600 kg/m3 is 0.60 g/cm3 (divide by 1000 and change units.)
• How does the density of oak compare to the density of water?
Solving problems
• D=m/v
• Solve for m
• Solve for v
Solve it
• A stainless steel sphere has a mass of 25 grams and a volume of 3.2 cm3. What is the density of the sphere?
• A cube has a mass of 7.8 grams. The length of the sides of the cube is 1.2 cm. What is the density of the cube?
Solve it, then compare
• Honey’s density is 1.4 g/cm3
• Write this as kg/m3
• Sandstone’s density is 20,280 kg/m3
• Write this as g/cm3
• Compare answers with with someone nearby.
Use a balance to find the mass

Use a graduated cylinder to find the volume (not a beaker – why?)

D = mass/volume

Determining Density
• Read the mark at eye level
• 1 mL = 1 cm3
Volume of solids
• Length X width X heights gives cubic centimeters
• What is the volume of a box that is 10” long, 5” wide, and 3” high?
• What is the volume of a box that is 2’ long, 1’ wide, and 9” high?
More volumes, use 3.14 for π
• Sphere: V=(4/3)πr3
• What is the volume of a sphere with a radius of 2 cm?
• Cylinder: V=πr3h
• What is the volume of a cylinder that is 10 cm tall and has a radius of 3 cm?
Irregular shapes
• Volume by displacement of fluid
• Remember: 1 mL = 1 cm3
• Fill graduates cylinder with fluid to known level (50 mL)
• Carefully slide object down the side of the cylinder
• Compute the increase in the fluid height
• 82 mL - 50 mL = 32 mL
• 32 mL = 32 cm3
Compute this
• I fill a graduated cylinder with 50 mL of water.
• I slip a stone into the cylinder and the water raises to 62 mL.
• What is the volume of the stone?
Why density varies
• Mass of each atom or molecule that that makes up the substance – a calcium atom has more ‘stuff’ in it than an oxygen atom.
• How tightly the atoms are packed -- the atoms are closer together in diamond that in graphite, but both are carbon.
• (Except for water) solids are more dense than liquids
• Liquids are more dense than gases