States of Matter
Solid, Liquid, and Gas
2
Steam
Ice
Heat
Water
Heat
A solid has definite size and shape.
A liquid has definite size but no definite shape. It takes the shape of its container.
A gas has neither definite size nor definite shape. It takes the size & shape of its container.
Density
Which weighs more, a kilogram of iron or a kilogram of feathers? The same!
Which is more dense, a kilogram of iron or a kilogram of feathers? The iron!
Density = Mass/Volume
Units of Density: g/cm3, kg/m3, g/mL
A rectangular solid has dimensions 8.0 cm long, 5.0 cm
wide, and 2.0 cm thick. It has a mass of 1.6 kg. What is its
density in g/cm3?
Volume = length x width x thickness
Volume = 8.0 cm x 5.0 cm x 2.0 cm
Density = Mass/Volume
Density = 1600g/80 cm3
Volume = 80 cm3
Density = 20g/cm3
Mass = 1.6 kg = 1600 g
Density of Water
Water has its maximum density at a temperature of approximately 4o C
1 g of water at a temperature of 4o C has a volume of 1 cm3 (1 mL).
1 cm3
Density = Mass/Volume
Density of Water = 1 g/cm3
Density of Water = 1 g/mL
If the density of an object is less than or equal to 1 g/cm3 , it will float.
If the density of an object is greater than 1 g/cm3 , it will sink.
Measuring Volume
Volume = length x width x thickness
V=LxWxT
Rectangular Solid
A
Volume = Cross Sectional Area x Length
V=AxL
A = πr2
L
Cylinder
V = πr2L
Measuring Volume of Irregular Solids
V2
V1
Irregular Solid
Volume of the irregular solid = Volume of water displaced
V = V2 – V1
Using the density of water to measure the volume of a container.
Determine the mass of the empty flask, m1.
Fill the flask with water.
Determine the mass of the flask & water, m2.
Empty Flask
Determine the mass water, m3 , as follows:
m3 = m 2 – m1
Use the density equation to find the volume.
Density = mass /volume
Volume = mass /Density
Volume = m3 /1g/cm3
Filled with water
Volume of the water = Volume of the Flask
SC
ALIN
G
Scaling
Side = 1 cm
Scale Factor = 1
Side = 2 cm
Scale Factor = 2
Area= 6 cm2
Volume = 1 cm3
Area/Volume = 6
Area = 24 cm2
Volume = 8 cm3
Side = 10 cm
Area/Volume = 3
Scale Factor = 10
Area = 600 cm2
Volume= 1000 cm3
Area/Volume = .6
Scale Factor = 1
Area/Volume = 6
Scale Factor = 2
Area/Volume = 3
Heat Loss is proportional to Area
Heat Production is proportional to Volume
Heat Loss/Heat Production = Area/Volume
Heat Loss is 6 times as great as the Heat
Production for the small cube.
Scale Factor = 10
Area/Volume = .6
Heat Loss is .6 times as great as the Heat Production for the cube scaled up by 10.
The small cube losses heat at 10 times the rate as the large cube.
Scale Factor = 1
Area/Volume = 6
Scale Factor = 2
Area/Volume = 3
Amount of skin is proportional to Area
Weight is proportional to Volume
Amount of Skin/Weight = Area/Volume
A pound of small potatoes has more skin
than a pound of large potatoes.
Scale Factor = 10
I you want to make mashed potatoes you get more with large potatoes.
Area/Volume = .6
Which is stronger: an elephant or an ant?
“She eats
like a bird.”
“He eats like a horse.”
Why does a fly often get water
logged and become unable to fly
from a body of water?