Post on 03-Jan-2016
description
Density
Created by Dr. A. Davila2010
Three Cubes of Three Different Types of Woods
Balance Scale
Pine Verses the Oak
Pine Verses the Poplar
A measurable physical property that can be found by dividing the
mass of an object by its volume.
Una propedad física que se puede medir; se puede calcular
dividiendo la masa de un cuerpo entre su volumen.
D = mv
densitydensidad
MASSmasa
The Kilogram (kg) is the SI unit for mass. The triple-beam balance or an electronic balance scale
may be used.
El Kilogramo (kg) es la unidad SI de masa. Se usa una balanza
Triple-Beam Balance(balanza de platillo)
Electronic Balance Scale (balanzas de
precisión)
gram (g)gramo (g)
• A unit for mass
• Una unidad de masa
1 gram = 0.35 ounces
= 1 gram
= 5 grams
Use the Triple-Beam Balance to measure mass (g)
Calibrate your Balance if the pointer is not centered on zero
Start by making sure the riders are on the zero setting
Turn Knob to right or left
Place your mass to be measured in the center of the clean pan. Slide the riders from slot to slot until the pointer is centered back
at zero
If not enough, move the next largest unit rider
Add together the beam positions of all three riders. This will be the mass of the object
measured.
The oak cube has a mass of 13 grams
VOLUMEvolumen
The Cubic meter (m3) is the SI unit for volume. A graduated cylinder can be used.
El metro cubico (m3) es la unidad SI para medir
volumen. Se usa una probeta graduada.
liter (L)litro (L)
• A unit measuring volume or capacity
• Una unidad de volúmen o capacidad
1000 mL = 1 L
946.35 mL =
1 qt.
meniscus
200 milliliters of water
Displacement of the water
due to the cubHow much water got displaced?
Displacement of the water
due to the cubHow much water got displaced?
Displacement of the water due to the
cube.How much water got displaced?
225
About 14.5 mL225
Three-Dimensionalincludes _________, ___________,
and _____________.Used to find ___________ of an
object.
Glue the net for a cubic centimeter
Glue the net for a cubic
inch
1 cubic inch is equal to _____ cubic centimeters
Length widthheight
VOLUME
V = 1 cm3
16.39
V = 1 in3
CC
milliliter (mL)millilitro (mL)
• A fraction of a liter (1/1000 L)
• 1 cubic centimeter is equal 1 milliliter
Una fracción de un litro (1/1000 L)
Un centimetro cubico es igual que 1 millilitro
1 cm3 = 1 mL (cc)
MASSmasa
The Kilogram (kg) is the SI unit for mass. The triple-beam balance or an electronic balance scale
may be used.
El Kilogramo (kg) es la unidad SI de masa. Se usa una balanza
Triple-Beam Balance(balanza de platillo)
Electronic Balance Scale (balanzas de
precisión)
VOLUMEvolumen
The Cubic meter (m3) is the SI unit for volume. A graduated cylinder can be used.
El metro cubico (m3) es la unidad SI para medir
volumen. Se usa una probeta graduada.
milliliter (mL)millilitro (mL)
• A fraction of a liter (1/1000 L)
• 1 cubic centimeter is equal 1 milliliter
Una fracción de un litro (1/1000 L)
Un centimetro cubico es igual que 1 millilitro
1 cm3 = 1 mL (cc)
A measurable physical property that can be found by dividing the
mass of an object by its volume.
Una propedad física que se puede medir; se puede calcular
dividiendo la masa de un cuerpo entre su volumen.
D = mv
densitydensidad
The oak cube has a mass of 13 grams and a volume of 16.5 milliliters
13 g16.5 mLD=
0.77 g/mLD=
Real World ApplicationDensity can be used to compute the
weight of a piece of machinery or part of a bridge or building before it is actually constructed. An engineer needs only to know the volume and density of the material of which it is to be made. The engineer can compute beforehand the load that each part of the structure will have to support. This will determine whether the design is of sufficient enough.
mVD=
Real World Application
• Density can also be used to differentiate a pure metal from an alloy, as in the classic case where Archimedes had to determine if Sicily’s king had a crown of pure gold or an alloy.
What Archimedes Measured
Weight of the gold that Hiero had given the jeweler)
Volume of water the gold displacedWeight of the crownVolume of the water the crown displaced
• What Archimedes Found Archimedes found that the jeweler’s crown displaced more water than the gold block.
• Archimedes Argument (Explanation) Archimedes reasoned that a gold crown should displace the same volume of water as the as the gold Hiero had given the jeweler. However, if it was not pure gold, but a silver alloy as the king suspected, that would increase the volume of the crown and displace more water.
http://www.crsep.org/PerplexingPairs/Jan.%2022.2003_Archimedes.pdf
• He observed that the jeweler’s crown displaced twice the volume of water displaced by the gold and concluded that the jeweler’s crown was not made from gold.
• Because gold weighs more than silver, he reasons that a crown mixed with silver would have to be bulkier to reach the same weight as one composed only of gold; therefore it would displace more water than its pure gold counterpart.
• Thus, Archimedes showed that water displacement was a good method for measuring the volume of irregular objects (as Archimedes certainly was!). An object immersed in water will displace a volume of water equal to the volume of that object.