Monday, September 13Monday, September 13Answer the following:Answer the following:

What is extrapolation?What is extrapolation?

Was it useful for you during the dice lab?Was it useful for you during the dice lab?

How did you use it?How did you use it?

Density!!!Density!!!

What is Density?What is Density?

The density of a material is defined as its The density of a material is defined as its mass per unit volume. mass per unit volume.

So what does that mean??So what does that mean??– How heavy something is in comparison to its How heavy something is in comparison to its

sizesize

What are the Units?What are the Units?

The proper SI unit is kg/mThe proper SI unit is kg/m33

We typically use g/mL or g/cmWe typically use g/mL or g/cm33

– Remember 1mL = 1cmRemember 1mL = 1cm33

How do we find mass?How do we find mass?

How do we find volume?How do we find volume?

Playing around with DensityPlaying around with Density

Take your piece of Modeling clayTake your piece of Modeling clay

Do what you can to make it float in the cup Do what you can to make it float in the cup of waterof water– What did you do?What did you do?

Do what you can to make it sink in the cup Do what you can to make it sink in the cup of waterof water– What did you do?What did you do?

Multi Flow MapMulti Flow Map

Make a Multi Flow Map showing how the Make a Multi Flow Map showing how the cause effected the Densitycause effected the Density

Piece of Clay

FLOAT

SINK

How does Density affect us?How does Density affect us?

In general, density can be changed by In general, density can be changed by changing either the pressure or the changing either the pressure or the temperature. temperature.

Increasing the pressure will increase the Increasing the pressure will increase the density of a material.density of a material.

Increasing the temperature usually Increasing the temperature usually decreases the density decreases the density

Thursday, September 16Thursday, September 16Today we will….. Today we will…..

Take a closer look at DensityTake a closer look at Density

Write and answer the following questions Write and answer the following questions in your notebook:in your notebook:

– What causes something to float on top What causes something to float on top of the water?of the water?

– What causes something to sink under What causes something to sink under the water?the water?

So what does Density have to do So what does Density have to do with the Titanic?with the Titanic?

When it hit the iceberg, it ripped open and When it hit the iceberg, it ripped open and the bottom filled with water the bottom filled with water – mass changed but not the volumemass changed but not the volume

Why else is Density important to us?Why else is Density important to us? It helps us to float!!!It helps us to float!!!

This is called BuoyancyThis is called Buoyancy

***Salt water is more dense so it makes it easier for us to float****

Density of water = 1Density of water = 1(100grams / 100ml of water)(100grams / 100ml of water)

Density > 1 = sinkDensity > 1 = sinkDensity < 1 = floatDensity < 1 = float

Practice with DensityPractice with Density

Density of water = 1Density of water = 1

Buoyancy = density less than or = 1Buoyancy = density less than or = 1

Rock has a mass of 10g and a volume of 5 mLRock has a mass of 10g and a volume of 5 mL– SinksSinks

Wood has a mass of 10 g and a volume of 20 cmWood has a mass of 10 g and a volume of 20 cm33 – FloatsFloats

To change Density, change the Volume!!!To change Density, change the Volume!!!– Air Craft carriersAir Craft carriers

Demo #1: Demo #1: Pepsi ChallengePepsi Challenge

PREDICT: Which of the following drinks PREDICT: Which of the following drinks will float in the water? (in, not on top)will float in the water? (in, not on top)

Record your observations (you may make Record your observations (you may make sketches) and provide an explanation for sketches) and provide an explanation for what took place in this demo. Be specific what took place in this demo. Be specific and include any change in the density and include any change in the density (mass and volume) of the resulting (mass and volume) of the resulting mixture.mixture.

Demo #2: Demo #2: WHAT IS 25 + 25?WHAT IS 25 + 25?

PREDICT: When 25 mL of isopropyl PREDICT: When 25 mL of isopropyl alcohol and 25 mL of water are combined, alcohol and 25 mL of water are combined, what will be the resulting volume?what will be the resulting volume?Record your observations (you may make Record your observations (you may make sketches) and provide an explanation for sketches) and provide an explanation for what took place in this demo. Be specific what took place in this demo. Be specific and include any change in the density and include any change in the density (mass and volume) of the resulting (mass and volume) of the resulting mixture.mixture.

Demo #3: Demo #3: WHATEVER FLOATS WHATEVER FLOATS YOUR BOATYOUR BOAT

PREDICT: Will aluminum foil (D = 2.7 PREDICT: Will aluminum foil (D = 2.7 g/cm3) sink or float when placed in water? g/cm3) sink or float when placed in water? Record your observations.Record your observations.PREDICT: How can aluminum foil be PREDICT: How can aluminum foil be altered to cause it to float? Record your altered to cause it to float? Record your observations.observations.Record observations and explain what Record observations and explain what happens as more mass is added to the happens as more mass is added to the foil. foil.

Demo # 4: Demo # 4: YELLOW YELLOW SUBMARINE?SUBMARINE?

PREDICT: Will a whole lemon sink or float PREDICT: Will a whole lemon sink or float in pure water? Record your observations in pure water? Record your observations (you may include sketches)(you may include sketches)

PREDICT:PREDICT: Will a peeled lemon sink or Will a peeled lemon sink or float in pure water? Record your float in pure water? Record your observations (you may make sketches)observations (you may make sketches)

Provide an explanation, including changes Provide an explanation, including changes in mass, volume and densityin mass, volume and density

Demo #5: Demo #5: HOT WATER – COLD HOT WATER – COLD WATERWATER

PREDICT: What will happen when the tube of PREDICT: What will happen when the tube of hot water is placed on top of the tube of cold hot water is placed on top of the tube of cold water?water?PREDICT: What will happen when the tube of PREDICT: What will happen when the tube of cold water is placed on top of the tube of hot cold water is placed on top of the tube of hot water?water?Record your observations (you may include Record your observations (you may include sketches) and provide an explanation for what sketches) and provide an explanation for what took place in this demo. List other situations took place in this demo. List other situations where can this concept be applied.where can this concept be applied.

DemosDemos

High fructose corn syrupHigh fructose corn syrup

21 teaspoons of sugar in pepsi21 teaspoons of sugar in pepsi

Aspartame – very bitterAspartame – very bitter

About the size of a packetAbout the size of a packet