what is density? what is the definition? a measure of how many particles that are packed into a...

What is Density?

What is the definition? A measure of how many particles that are

packed into a certain area.

What is the formula?Density = Mass / Volume

More dense = more particlesLess dense = less particles

Density

How do you get the mass of an object?

Solids? Liquids?

How do you get the volume?Cubes? Irregular Shapes?

Could water displacement have been used to get the volume of the wood? Why???

Density of pure water = 1.0 g/ml

If an object has a density greater the 1.0 g/ml it will sink in water.

If an object has a density less than 1.0 g/ml it will float in water.

So. . . This means that knowing the density of an object lets you know if it will sink or float in water.

But. . . What if the density was exactly 1.0 g/ml?

Does the sample size affect the density of an object???

In other words, if you break a piece off of an object. . . Will it have a different density than the whole piece?

NOOOOOOO!!! Density is based on total mass divided by total volume. When one changes, the other also changes, so the density stays the same!!!

Will hardwoods have higher density than softwoods?

Yes, hardwoods on average are a little higher density.

Hardwoods: Oak, Walnut, MapleSoftwoods: Pine, Cedar, Fir

What does this mean? More molecules are packed into hardwoods making them denser which means that they soak up less water than softwoods.

Do liquids have different densities???

Of course. . . So what happens when you mix them together???

They form layers with the highest density falling to the bottom.

Alcohol = .80 g/mlVegetable Oil = .90 g/mlWater = 1.0 g/mlSalt Water = 1.2 g/ml

Would the density of a liquid change how you float in that liquid???

Denser liquids help you float easier. That is why it is easier to float in the ocean Than in a freshwater lake.

Do metals have different densities?

Yes. . . Lead density 11.1 g/cm3

Aluminum density 2.8 g/cm3

These are all over 1.0 g/ml and most ships are made of metal???

So how do they float???

Remember. . . Warm air rises.

So this means warm air is less dense than cold air

Does the temperature of air affect how dense it is???