Density of Diamond and Paraffin
Carbon atom
Hydrogen atom
Molecule
Diamond
(density = 3.5 g/cm3)
Paraffin
(density = 0.87 g/cm3)
Hydraulics and Pascal’s Principle
Small force is applied
over a small area.
Larger
distance
Pascal’s law:
The pressure applied in a closed
container is transmitted equally
in all parts of the fluid.
Large force is
produced over
a much larger area.
Shorter
distance
A small force exerted over a large distance is traded for a large force over a small distance.
Solving Problems:
Pressure and Force
PRESSURE
Pressure = Force
Area
FORCE
Force = Pressure × Area
Units of Pressure
Pressure is force per unit of area.
Pascal
PSi
1 lb
1N
1 in2
One Psi is
one pound
of force
per square inch.
1 m2
One pascal is
one newton
of force
per square meter.
Archimedes’ Principle
Free body
diagram
Free body
diagram
N
N
10
20
29.4 N
Mass = 3 kg
Volume = 1,000 cm3
10
Scale
29.4 N
19.6 N
20
30
30
40
40
50
50
Weight
29.4 N
Water
Scale
19.6 N
Weight
29.4 N
Buoyant
force
9.8 N
Average Density
Average density is the total mass divided by the total volume.
Solid steel ball
Hollow steel ball
volume = 25 mL
mass = 195 g
volume = 25 mL
mass = 20 g
Average density = 195 g
25 mL
Average density = 20 g
25 mL
Average density = 7.8 g/mL
Average density = 0.8 g/mL
SINKS!
FLOATS!
Density and Buoyancy
The
steel ball
sinks
Weight
The buoyant force
is the same!
The weight is different
The
wood ball
floats
Weight