grade 8 science chapter 5 density and buoyancy chapter 5 density and buoyancy

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Grade 8 Science Chapter 5 Density and Buoyancy

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Page 1: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Grade 8 ScienceGrade 8 Science

Chapter 5

Density and Buoyancy

Chapter 5

Density and Buoyancy

Page 2: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Chapter 5.1Chapter 5.1Chapter 5.1Chapter 5.1

Density and Buoyancy

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Page 3: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

DensityDensityDensityDensity

Density – The amount of mass in a certain volume of a substance

A “heavy” substance has a high density

A “light” substance has a low density

Density – The amount of mass in a certain volume of a substance

A “heavy” substance has a high density

A “light” substance has a low density

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Page 4: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

DensityDensityDensityDensity

Density can be described as the crowdedness of the particles in a substance

Density can be described as the crowdedness of the particles in a substance

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Page 5: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Density and States of Density and States of MatterMatterDensity and States of Density and States of MatterMatter

In general, gases are less dense than liquids, and liquids are less dense than solids.

In general, gases are less dense than liquids, and liquids are less dense than solids.

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Page 6: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Density and States of Density and States of MatterMatterDensity and States of Density and States of MatterMatter

The only way a pure substance can change density is to change state.

The only way a pure substance can change density is to change state.

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Solid gold is MORE dense than molten

(liquid) gold.

Page 7: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Chapter 5.2Chapter 5.2Chapter 5.2Chapter 5.2

Density: How are Mass and

Volume Related?

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Page 8: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Density – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs Volume

Mass – The amount of particles in a substance

Volume – The amount of space occupied by a substance

Mass – The amount of particles in a substance

Volume – The amount of space occupied by a substance

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Page 9: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Formula for Density:

Density (D) =

Formula for Density:

Density (D) =

Density – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs Volume

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Mass (m)Volume (V)

Page 10: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Example

The density of an object having a mass of 10g and a volume of 2 cm3 is…

D = = = 5 g/cm3

Example

The density of an object having a mass of 10g and a volume of 2 cm3 is…

D = = = 5 g/cm3

Density – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs VolumeDensity – Mass vs Volume

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m 10gV 2cm3

Page 11: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Chapter 5.3Chapter 5.3Chapter 5.3Chapter 5.3

Buoyancy: The “Anti-Gravity”

Force

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Page 12: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Why things Float…Why things Float…Why things Float…Why things Float…

Floating – when an object does not fall or sink, but suspends in a fluid

Floating – when an object does not fall or sink, but suspends in a fluid

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Page 13: Grade 8 Science Chapter 5 Density and Buoyancy Chapter 5 Density and Buoyancy

Buoyancy ForceBuoyancy ForceBuoyancy ForceBuoyancy Force

Gravity – force that pulls objects down

Buoyancy – force that pushes objects up

Gravity – force that pulls objects down

Buoyancy – force that pushes objects up

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