Transcript Feathers vs Rocks (pg 45)

DN: Feathers vs Rocks (pg 45)
• 100 pounds of
feathers
• 100 pounds of
rock
Which has the greatest:
A) Volume?
B) Mass?
C) Density ? Explain each answer
Which is less dense: ice or water?
Mass
• Mass is the amount of matter (“stuff”) in a
substance
• Measured with a scale
Volume
• The amount of space something takes up
Density
It is a measure of how tightly packed and how heavy
the molecules are in an object.
(Density is the amount of matter within a certain
volume.)
Practicing with Volume….
• Calculate the volume of the following
objects. Show ALL variables and work,
even if using a calculator.
1.
2.
3.
4.
Green Textbook
Blue textbook
Your lab tray
Your table top
Green Textbook
Blue Textbook
Lab Tray
Table top
Units for density
Formula: M = mass
3
g/cm or
g/ml
V= volume D = density
To find density:
1)
Find the mass of the object
2)
Find the volume of the object
3)
Divide : Density = Mass Volume
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of
space, calculate the density.
To find density:
1)
Find the mass of the object
2)
Find the volume of the object
3)
Divide : Density = Mass Volume
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of
space, calculate the density.
Set up your density problems like this:
Given: M =
Unknown: D=?
V=
Formula: D = M / V
Solution:
A lead cylinder has a mass of 540 grams and a
density of 2.70 g/ml. Calculate the volume of the
lead cylinder.