Monday September 21, 2009 Day 4- EVEN Homework: NONE

Monday September 21, 2009 Day 4- EVEN

Homework: NONE

Do Now: Why do you think

some objects float and others sink?

◦EXPLAIN YOUR ANSWER!

Homework: NONE

Float or Sink?

Will a can of soda float or sink?

Does it matter what kind of soda we use?

What makes one can float and another sink?

Does it depend on the object’s size?

Same VolumeVolume (cm3,mL)

(Amount of space occupied)

What makes one can float and another sink?

How about the mass?

Different Mass

Amount of matter that an Amount of matter that an object contains (g)object contains (g)

Density (g/cm3 or g/L)Amount of substance contained

within a given space

Density = Density = mass/volumemass/volume

Which cube is more dense?

A B

A - has more mass per unit of volume

Another way to think about it…

As the volume remained the same….…. the mass increased.

Did the density of the bus increase or decrease?

Increased

Let’s try some other objects…

Golf ball Styrofoam ball

Can of Diet Coke Can of Coke

Wooden ball Paperclip

Tuesday, September 22nd

Homework: NONE

Do Now: Complete #6- Float or Sink

Record the data from “Float or Sink”

Calculate the densities of each object and record◦ Try to determine whether the object will float or sink

Complete #8

Homework: NONE

Object Mass Volume

1 DietSoda

352.6 g

355 mL

2 Regular

Soda

376.2g

355 mL

3 GolfBall

45.8g

40 mL

4 WoodenBall

84.6g

110 mL

5 Styro-foam

3.5 g 11 mL

6 PaperClip

1.5 g 0.7 mL

What is density?What does it involve?

Objects float on top of the liquid.

Water is on the bottom, because it was poured in first.

Density is the thickness of something

The more air pockets in something the more it will float. Wax, ice, has lots of air pockets in it and floats.

Liquids are liquids and will all mix together

Weight determines if an object will sink or float.

Heavy objects always sink and light objects always float.

A larger heavier object will not float as well as a smaller lighter object of the same material.

The amount of water will cause objects to float or sink better.

There must be more water for larger objects to float. Weight of the water must be more than the weight of the object.

Objects with holes will always sink.

Will it float in water? Determine if the following shapes will float in water by calculating the density for each item.

Density = Mass / Volume

Mass: 15 gVolume: 20 mL

Mass: 1000 gVolume: 50 mL

Mass: 225 gVolume: 100 mL

Mass: 10 gVolume: 200 mL

If the density is less than 1.0 g/mL then it will float.

Will it float in water? Determine if the following shapes will float in water by calculating the density for each item.

Density = Mass / Volume

Mass: 15 gVolume: 20 mLDensity:

0.75 g/mL

Mass: 1000 gVolume: 50 mLDensity:

20.0 g/mL

Mass: 225 gVolume: 100 mLDensity:

2.25 g/mL

Mass: 10 gVolume: 200 mLDensity:

0.05 g/mL

If the density is less than 1.0 g/mL then it will float.

To calculate density, you need to know the mass and volume of the object….

How are you going to measure the mass?

What are the units for mass?

grams (g)

Measuring Volume

Liquids = milliliters (mL)

How will you measure the volume of a solid object?

Volume = a x a x a = a3

Volume = (4/3)πr3

(Length x width x height)

What are the units for volume of a solid object?

METRIC!!!!5.40 cm

Calculate the volume of this solid

5.40 cm3.20 cm

4.50 cm

Volume = 77.76 cm3

5.40 cm x 3.20 cm x 4.50 cm

If this solid has a mass of 132.0 g, what is its density?

Volume = 77.76 cm3

132.0 g / 77.76 cm3

Density = 1.7 g/cm3

Units of Density

1 g/mL = 1 g/cm3

(liquids) (solids)

Wednesday, September 23rd

Calculating Density of a Liquid

Do Now:•Fill out the Hearing Screening Form

•Name, Grade/HR

•Volume of a Liquid

•Finish Calculating Density Lab

•Homework: Density Calculations

Calculating Density Lab (Part II)

Identify the following lab Identify the following lab equipment: equipment:

Identify the following lab Identify the following lab equipment: equipment:

Test Test tubestubes

Measuring Liquid Volume

Meniscus

9.0 mL

What is the volume of this liquid?50 mL

45 mL

40 mL

45.0 mL

A liquid has a mass of 32.0 g. The volume of the liquid is as seen below. What is the liquid’s density?

95 mL

85 mL

Is it more or less dense than water?

0.4 g/mL

Less dense than water

Thursday, September 24 Do Now:

Come up with as many words possible associated with Density (WORDSTORMING)

Take HW out to be checked

HW- NONE

1. A block of aluminum occupies a volume of 15.0 mL and its mass is 40.5 g. What is its density?

2. What is the mass of the ethanol that exactly fills a 200.0 mL container? The density of ethanol is 0.789 g/mL

3. A rectangular block of copper metal weighs 1896 g. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, what is the density of copper?

4. What volume of silver metal will weigh exactly 2500.0 g. The density of silver is 10.5 g/cm3.

5. Find the mass of 250.0 mL of benzene. The density of benzene is 0.8765 g/mL.

6. A block of lead has dimensions of 4.50 cm by 5.20 cm by 6.00 cm. The block’s mass is 1587 g. From this information, calculate the density of lead.

Friday, September 25TABLE OF CONTENTS11. Float or Sink?12. Calculating Density

Lab I I HAVE, IF NOT, YOU

NEED TO HAND IT IN13. Density Calculations

WS14. Wordstorming:

DENSITY15. Calculating Density

Lab II16. Archimedes and the

Golden Crown17. Calculating Density

Lab III

Do Now:•Organize Binder

_________________________

•When finished, read Archimedes and the Golden Crown

•Solve the dilemma

•Calculating Density II and III

•Homework: NONEHomework: NONE

•Unless you have Lab Unless you have Lab Calculations to finishCalculations to finish

Archimedes and the Golden

Crown

The king wants to pick out a new crown but only wants one made of 100% pure gold, not gold plated or mixed with other metals. Can you help him find his new gold crown?

The volume of each crown is 60 cm3

D = M / V

A = 680.4 g

B = 534 g

C = 1,158 g

D = 1,284 g

Densities of Metals

Lead – 11.34 g/cm3

Gold - 19.3 g/cm3

Silver - 10.5 g/cm3

Platinum - 21.4 g/cm3

Copper - 8.9g/cm3

D = M / V

A = 680.4 g

B = 534 g

C = 1,158 g

D = 1,284 g

The volume of each crown is 60 cm3

Monday, September 28 Do Now:

◦Directions for Density Sketch

◦Finish Calculating Density Lab III Show me Lab II and III

◦Work on Density Sketch with group from Density Labs

◦When finished, MORE DENSITY PRACTICE!

Homework: Read pg. 25-27 and complete Review and Reinforce 1-2

Density “Sketch” Step-by-Step procedure for calculating

density◦Regular solid◦Liquid◦Irregular solid

Formula for calculating density (UNITS)

Picture that demonstrates density

Definition of density

Density picture