Sink and Swim

Ms. ScillieriMemorial School6th Grade Science

Misconceptions

• A lot of people believe that objects float in WATER because of mass. Just

being heavy or light

Density

• Scenario:• A tree trunk falls during a storm and ends up in the ocean it FLOATS, even though it has a mass of hundreds of

pounds.

• This is because of density• I know you must be saying • “Density what is that?!”

Let’s Think About It

• A block of wood cut into a cube

It is 10 centimeters long on each side and has a weight of 500 grams

Now think about a block of gold cut into the same cube with 10 centimeters on

a sideWhat will have more mass the gold or

wood?

Conclusion

• The block of gold has a mass of 11,000 grams. The wood only 500 grams

• The two cubes are the same size, or take up the same amount of space VOLUME,

but there is more mass in gold than wood. Making it more dense

So….

• Density is a comparison of how much mass there is in a certain amount of

space. ( OR VOLUME)

Which one is more dense

• Let’s pretend it is people in a room

Now which one?

Units of Density

Solving for Density

• Formula: Mass/Volume• Units: Grams and

Centimeters3 • Practice Problem:• If your notebook has a

mass of 500 grams and a volume of 40 centimeters cubed what is the density

• Step One: Write Formula

• Step Two : Find Mass and Volume

• Step Three: Plug into Formula

• Step Four Solve

Practice Problem

• Density= Mass/Volume• Mass= 500 grams• Volume= 40 centimeters cubed• Density= 500grams/40 cms3• Density = 10 grams/cm3

• Questions???• Don’t worry we will practice this A

LOT MORE ON WEDNESDAY!!

Big Ideas

• ONE BIG IDEA BEHIND WHY SOME THINGS FLOAT IN WATER OR ANY OTHER

LIQUID• If it is LESS DENSE THAN THE LIQUID it FLOATS• If it is MORE DENSE THAN THE LIQUID it SINKS

• The density for water is 1.0 g/cm3

What will sink and what will float in water?

Material Density

A piece of wood 0.5 g/cm

A piece of wax 0.9 g/cm

A piece of copper 9.0 g/cm

Density of Irregular Shaped Objects

• Would be able to measure LENGTH, WIDTH, and HEIGHT of something like a jagged pebble, a ball,

or a toy car?• How would you go about finding density? (Hint

use water, think about what happens when you get into a pool or bathtub)

Let’s Take A Look

• Step One: Write the formula• Step Two: Find the mass of the irregular shaped

object . How?• Step Three: Fill a beaker with water in mL.• Drop the item in the water submerging it or

covering it. difference in water is the volume.• Now how would we finish solving

Let’s Experiment

Liquid LayersWhat do you think will happen if we pour corn syrup, vegetable oil, and

water one by one in a clear container?

Liquid Layers Lab

• Break up into your lab groups quickly and quietly!• Let’s chat and come up with a hypothesis• On the back supply table each group has a clear beaker,

200mL of water colored blue, 200 ml of corn syrup, and 200 mL vegetable oil.

• Carefully send 2 people over and take your beaker and fluids

• When I say go we will pour each fluid in one at a time and in the end we get something that…

Lab Questions

• What is the formula for density?• What is the density of water?• What happens if you pour together liquids

that have different densities?• Will the liquid on the top have the highest or

lowest density?• Will the liquid on the bottom have the highest

or lowest density?

Looks like this!!!

HOMEWORK1. How would you define density?

2. What is the formula and units for density

SUPER SCIENCE QUESTION!!!!

If Hunter and Samantha have a book, a scale, and a ruler how would they be able to find density?