Notes Science

Essential Question(s)What is density? What is mass? What is volume? How do I calculate density? How do I multiply and divide with decimals?

Tennessee SPI Objective:Apply an equation to determine the density of an

object based on its mass and volume

Check for UnderstandingCalculate the density of various objects.

SPI 0807.9.7 Density

SPI 0807.9.7 Density

What is density? Density is the amount of matter (mass)you have crammed in a given space (volume)Reminder: mass is how much matter is in an object The unit for mass is grams (mg or g or kg)Reminder: volume is how much space it takes up (size) Unit for solid volume is cubic meters (cm3 or m3 or km3) Unit for liquid volume is liters (mL or L or kL)

To compute density - divide the mass by the volume of the object

ScienceNotes

Demonstration:Demonstrate with wadded up paper in a trash can

Density Example: Here are two objects that are the same size. (1) Bowling Ball and (2) Soccer Ball One of these objects contains more matter (bowling ball). With two same-sized objects like this, the object with more

mass has greater density than the other object.

More Dense Less Dense

SPI 0807.9.7 Density ScienceNotes

Soon you will get your first driver’s permit. The place where you receive your driver’s permit is called the DMV (Department of Motor Vehicles) Think of DMV for density

SPI 0807.9.7 Density ScienceNotes

Density Formula

Use this formula: Density = mass divided by volume

or or

Memory Trick

Quick Practice

SPI 0807.9.7 Density Science

Solve the Density Problem Shown BelowGo ahead and use a calculator (for now)

1) Calculate the density of an object with a mass of 25g and a volume of 10cm3

Example: 25 (mass) divided by 10 (volume)Density= 10 25

Units…g/cm3

Answer 25g ÷ 10cm3 = 2.5 g/cm3

Don't Forget Your Units!Example: grams/centimeter cubed

Written like this…g/cm3

Quick Practice

SPI 0807.9.7 Density Science

Solve the Density Problem Shown BelowGo ahead and use a calculator (for now)

Don't Forget Your Units!Example: grams/centimeter cubed

Written like this…g/cm3

2) Calculate the density of an object with a mass of 45kg and a volume of 43m3

Example: 45 (mass) divided by 43 (volume)

Density= 43 45

Units…kg/cm3

Use this formula: Density=mass divided by volume

Quick Practice

SPI 0807.9.7 Density Science Solve The Three Density Problems Shown Below

Go ahead and use a calculator (for now)

Density= volume mass

2) Calculate the density of an object with a mass of 45kg and a volume of 43m3

Example: 45 (mass) divided by 43 (volume)

Density= 43 45

D= M/V or orMV

D=

Units…kg/cm3

(round up to the nearest hundredth)

45kg ÷ 43m3 = 1.05kg/m3

Use this formula: Density=mass divided by volume

Quick Practice

SPI 0807.9.7 Density Science Solve The Three Density Problems Shown Below

Go ahead and use a calculator (for now)

Density= volume mass

1) …density of an object with a mass of 25g a volume of 10cm3? Example: 25 (mass) divided by 10 (volume)

2) …density of an object with a mass of 45kg a volume of 43m3?Example: 45 (mass) divided by 43 (volume)

3) …density of an object with a mass of 350g a volume of 95cm3 ? Example: 350 (mass) divided by 95 (volume)

Density= 10 25

Density= 43 45

Density= 95 350

D= M/V or orMV

D=

Units…g/cm3

Units…kg/cm3

Units…g/cm3

Answers1) …density of an object with a mass of 25g & volume of 10cm3?

25g ÷ 10cm3 = 2.5g/cm3

3) …density of an object with a mass of 350g & volume of 95cm3 ? (round up to the nearest hundredth)

350g ÷ 95cm3 = 3.68g/cm3

SPI 0807.9.7 Density ScienceNotes

Density=mass divided by volume

Don't Forget Your Units!Example: grams/centimeter cubed

Written like this…g/cm3

1) Identify which liquids would occupy levels A, B, and C according to their density.

Level C

Level B

Level A

Designation Substance Density

Liquid 01 Water 1.0 g/mL

Liquid 02 Liquid Mercury 13.6 g/mL

Liquid 03 Turpentine 0.8 g/mL

Turpentine (0.8 g/mL)Water (1.0 g/mL)Mercury (13.6 g/mL)

SPI 0807.9.7 (Density)ANSWERS

ScienceNotesSPI 0807.9.7

Density Density In Liquids

Lower density liquids will float on top of liquids with higher densityExample: Oil floats on top of water

SPI 0807.9.7 Density

ScienceNotes

Density In LiquidsLower density liquids float on top of liquids with higher densityHigher density liquids will sink below lower density liquids

View this YouTube Video Clip:Link: 7-Layer Density Column

Mass: 12g Volume: 3cm3

Mass: 23g Volume: 5cm3

Mass: 11g Volume: 3cm3

Mass: 19g Volume: 7cm3

(A)

(D) (C)

(B)

4 g/cm3 2.71 g/cm3

3.6 g/cm3 4.6 g/cm3

ScienceNotesSPI 0807.9.7

Density Which cube below has the GREATEST density?Again…go ahead and use a calculator (for now)