1 Temperature
Unit 6: Heat
Temperature Scales and
Absolute
b l
Temperatures
2 Temperature
Learning Goal:
I can define temperature and heat and
can describe the relationship between
them.
them
you learned y
yesterday,
y how
Based on what y
well can you:
Define heat?
D fi
Define
ttemperature?
t
?
Describe how they are alike and how they
are different?
3 Temperature
Review - Temperature
Temperature, which is the degree of
“hotness” or “coldness” of an object, is
proportional to the average translational
kinetic energy of the atoms and
molecules make up the substance.
Temperature is not a measure of the total
kinetic energy in a substance.
substance
Temperature is not a measure of total
thermal energy.
4 Heat vs. Temperature
Review - Heat vs. Temperature
Heat
Temperature
1
1.
Thermal Energy
KE + PE
1
1.
2.
For the whole
substance
2.
3.
Measured in
calories or joules
3.
Average
Translational Kinetic
Energy
For each particle in
the substance
Measured in
degrees
5 Temperature
Learning Goal:
I can define temperature and heat and
can describe how temperature scales are
used.
used
you how well can y
you:
Based on what y
Define heat?
Define temperature?
What is a temperature scale?
How is it used to measure temperature?
6 Temperature
Temperature Activity
7
Temperature Scales
What can you tell me about
temperature scales based on
our activity?
8 Temperature
Temperature Scales
Temperature is a quantity that
corresponds to degree of hotness on a
chosen scale.
A thermometer takes advantage of
the fact the most substances expand
with temperature.
A thermometer measures temperature
by comparing the expansion or
contraction of a liquid (red alcohol) in
i
increments
t on a scale.
l
9 Temperature
Temperature Scales
The Celsius temperature scale is
the scale used most often in the
world today.
y
The scale is named after Anders
Celsius who first suggested that a
scale with 100º between the
freezing and boiling point of
water would be a good idea.
10
Temperature
Temperature Scales
The Fahrenheit temperature scale
is the scale commonly used in the
US.
On the Fahrenheit temperature
scale, water freezes at 32º and
boils at 212º.
11 Temperature
CHECK YOUR NEIGHBOR
True or false:
Cold is the absence of fastg molecules.
moving
False; cold refers to very slowmoving molecules, not their
absence.
12 Absolute Temperature
Absolute Temperatures
Is there an absolute upper limit and
lower limit temperature?
What would an maximum temperature
be measuring?
g
Is there a point where the particles
couldn’t move any faster?
Theoretically, temperature has no
upper limit.
13 Absolute Temperature
Absolute Temperatures
What would an minimum temperature be
measuring?
Is there a point where the particles
couldn’t
ld ’t move any slower
l
– that
th t is
i they
th are
stopped?
Yes! The absolute lower limit for temperature
is called Absolute Zero
The particles have lost all their kinetic
energy and
d can’t
’t gett any colder
ld
14 Absolute Temperature
Absolute Temperatures
The Kelvin temperature scale was
developed to help explain the
relationship temperature and kinetic
energy (movement)
0 Kelvin (K) is Absolute Zero
273 K is the melting point of water (0º C)
373 K is the boiling point of water (100º C)
15 Temperature Conversion
Converting Between Scales
Do you think it is possible to convert a
t
temperature
t
measured
d on one
scale to a different scale?
Yes! You just need to use an
algebraic equation to
convert from one scale to the
other.
16 Temperature Conversion
Converting Between Scales
ºC = 5/9 (ºF - 32)
ºC = K + 273
In FPS, we are going to
use the Celsius scale
f our measurements
for
t
so you won’t need to
convert!
17 Temperature
Reflection
Mark your calendar!
TToday’s
d ’ learning
l
i
goal:l
I can define temperature and heat
and can describe how
ho temperature
temperat re
scales are used.
Using the scale, how do you think you
are doing with the concept?