- By
**leala** - Follow User

- 74 Views
- Uploaded on

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

**An Image/Link below is provided (as is) to download presentation**
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.

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 DensityUsing a graduated cylinder

- Read the mark at eye level
- Read volume at center of meniscus (ask your teacher!)
- 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

Ticket Out: Answer this

- Which has more mass, a pound of bricks or a pound of feathers?
- Which is more dense, a pound of bricks or a pound of feathers.

Download Presentation

Connecting to Server..