DENSITY-

NOTES ON DENSITY

I Density(D)

• An object’s mass compared to its volume

• On Earth we can sometimes use weight for mass.

IV Density Facts

• Things with HIGH Density: Bowling Ball Shot put

• Big Marble

• Things with LOW Density: Soccer Ball Soft Ball

• Ping Pong Ball

I Density(D) Terms

• Mass = how many atoms is in an object (kind of like weight)

• Volume = how much room (space) an object occupies.

• Matter = anything has mass and volume.

I Density(D) Terms

• Mass = grams (or kilograms)

• Volume = milliliters (ml) or cubic centimeters (cc or cm3) , liters (L)

II Density Definition(def)

• Density = how much stuff (matter) is in an object’s volume.

• Density = mass divided by volume

• D = M (mass) D = V M V (volume)

II Density Definition(def)

M

D Vx

III Measuring Density • MASS-use a balance scale

• Volume-– Calculate volume: (L x W x H)

length x width x height

• Volume- Example: 10 cm x 5 cm x 2 cm =

• 100cm3

III Measuring Density • MASS-use a balance scale

• Volume-– Displacement: put object in a

graduated cylinder and see how much the water level rises.

III more-Measuring Density

• 15 ml add marble 20ml

• What is the difference? This is the volume of the marble.

15 ml20 ml

IV more- Density Facts• Pure water (H2O) has a density

of 1.0 g/cm3

• That means: 1 gram of H2O has a volume of 1 cm3

• 1 cm3 = 1 ml = 1 g of H2O

Why do things float?

Why do things float?

Why do things float?

•Mass = 42,116,363 Kg

Why do things float?

•Mass = 42,116,363 Kg

• Volume = 44,070,909 L

•It is bigger than it is heavy

•So it will float

Hey…what’s all that stuff floating out there…it must have a low density…

let’s not worry about it.?

Ouch!

Yikes!

•Mass = 42,999,363 Kg Volume = 44,070,909 L

•Yikes…the mass is increasing due to water inflow

•But the volume is staying the same!

•D =42.9 / 44.0 =.97

Yikes!

•Mass = 43,256,363 Kg Volume = 44,070,909 L

•Yikes…the mass is increasing due to water inflow

•But the volume is staying the same!

•D =43.2 / 44.0 =.98

Yikes!

•Mass = 43,943,363 Kg Volume = 44,070,909 L

•Yikes…the mass is increasing due to water inflow

•But the volume is staying the same!

•D =43.9 / 44.0 =.99

Yikes!

•Mass = 44,060,363 Kg Volume = 44,070,909 L

•Yikes…the mass is increasing due to water inflow

•But the volume is staying the same!

•D =44.0 / 44.0 =1.0

Why do things float?

Things float if their density is less than the density of H20

Why do things sink?

Things sink if their density is larger than the density of H20

Why do things float?

• Tonnage (gross): 46.328 tonsDisplacement at time of collision: 48,478 tons (figures vary)

• Mass = 42,116,363 Kg• Volume (displacement) = 44,070,909 L• Density = M/V = 42,116,363 Kg / 44,070,909 L = 0.96

Kg/L

Why do things float?

Why do things float

• A thing will float if its mass is smaller than its volume.

• A thing will sink if its mass is bigger than its volume

Metric Prefix’s• Giga x 1,000,000,000 (billion)• Mega x 1,000,000 (million)• Kilo x1000 Hecto x100• Deka x10 • Meter, Liter, Gram • Deci 1/10• Centi 1/100 Milli 1/1000 • Micro 1/1,000,000