HEAT AND
TEMPERATURE
TABLE OF CONTENTS
Today we are going to tackle:
1.1 : What is the difference between heat and temperature
- What is Heat and Temperature?
- What is Internal Energy?
- What is Change of Phase?
1.2: Heat
1. Modes of Heat Transfer
- Conduction
- Convection
- Radiation
2. Sources of Heat
a. Natural
b. Artificial
1.3: Temperature
1. Thermometer
2. Celsius, Fahrenheit, Kelvin
3. Temperature Conversion Formulas
HEAT AND TEMPERATURE
HEAT
The total energy of all the
molecular motion inside that
object
- Energy in Transit
- moving from a body of
higher temperature to one
of lower temperature
- Flow of KE
SI Unit Heat: Joule (J)
TEMPERATURE
It is the measure of the
thermal energy or average
heat of the molecules in a
substance.
- Average KE
SI
Unit
Kelvin (K)
Temperature:
HEAT AND TEMPERATURE
HEAT AND TEMPERATURE
For example, the temperature of a small cup
of water is the same as the temperature of a
tub of water, But the tub of water has more
heat because it has more water and thus
more total thermal energy.
INTERNAL
ENERGY
TOTAL of all energies.
When a substance takes in or gives off heat,
its internal energy changes.
In
some cases, as when ice is melting, a
substance absorbs heat without an increase in
temperature.
The substance then changes phase.
INTERNAL
ENERGY
2. A substance contains internal energy, not heat.
3. Absorbed heat may make the molecules of a substance
jostle faster.
Energy in other forms:
1. Rotational kinetic energy of molecules.
2. Kinetic energy due to internal movements of
atoms within molecules.
3. Potential energy due to the forces between
molecules.
Change of Phase
As the HEAT energy of an object is absorbed or
released, the state of an object changes.
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1.2
Heat
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Modes of HEAT
TRANSFER
1.
-
CONDUCTION:
Transfer of energy within
materials and between
different materials that are
in direct contact.
- Materials that conduct heat
well are known as heat
conductors.
2. CONVECTION:
- In convection, heat is
transferred by movement of the
hotter substance from one place
to another.
3. RADIATION
-
Heat is transmitted in the
form of radiant energy
(electromagnetic waves).
-
Radiation from the sun is
primarily light.
- The sun’s heat is transmitted
by another process.
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Sources of HEAT
(Natural)
1. The Sun
Much of the heat on earth
may be traced back to the
sun.
- It is the sun’s heat that makes
plants grow. These plants
provide food for animals
which you in turn eat to
provide
yourself
with
needed energy.
2. The Interior of the Earth
A great amount of heat
came from buried hot rocks
and lava that flows craters
and crevices of erupting
volcanoes.
- The hot springs in Tiwi, Albay
and in Los Baños and the
boiling mud of Lake Agco,
Kidapawan are proofs that
the earth’s interior is much
hotter than its surface.
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Sources of HEAT
(Artificial)
1.
Chemical action
- fuels like coal, kerosene, wood
and gasoline are burned they are
used as artificial sources of heat.
- Our own body
2. Mechanical energy
-
-
Rumford and Joule sowed
that mechanical energy can
be transformed into heat
energy.
Rubbing hands together can
generate heat energy
Pumping air into a basketball
makes the cylinder and
needle hot
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Sources of HEAT
(Artificial)
3. Electrical energy
-
Electricity is very common
source of heat at home.
-
The
toasters,
ovens,
electric
irons,
electric
stoves, etc, are heated by
the resistance of the
heating coils to the current
passing through them.
4. Nuclear energy
-
The tremendous amount of
energy
from
nuclear
reactions can be used to
change water into steam,
which is then used to
operate a turbine to
generate electricity.
1.3
Temperature



A measure of the average kinetic energy of
atoms and molecules in a body.
The higher the temperature of a substance, the
faster is the motion of its molecules.
The quantity that tells how hot or cold
something is compared with a standard.
THERMOMETER
An instrument that measures temperature
by means of the expansion and
contraction of a liquid, usually mercury of
colored alcohol.
Boiling point (100)
Freezing point (0)
Divided in a
hundred equal
parts called
DEGREES.
CELCIUS
THERMOMETER
FARENHEIT
THERMOMETER
ANDERS CELCIUS
DANIEL GABRIEL FAHRENHEIT
Swedish astronomer
German physicist
KELVIN SCALE
WILLIAM THOMSON
“Lord Kelvin”
Scottish-Irish Physicist
First devised the scale
This calibrated thermometer
has been called a
Centigrade Thermometer
-
Boiling Point: 212
Freezing Point: 32



Used by scientists.
Unlike
Celcius
and
Fahrenheit,
Kelvin
is
referred to as a unit rather
than a degree.
A single Kelvin is equal to
a single degree on the
Celcius scale.
1.3
KELVIN SCALE
Its zero point is -273 ̊C, usually referred to as
“absolute zero,”
- the temperature at which matter is said
to have lost all its energy.
Scientific research uses the SI scale—
the Kelvin scale.
•
•
•
•
Degrees are the same size as the Celsius degree
and are called “kelvins.”
On the Kelvin scale, the number 0 is assigned to
the lowest possible temperature—absolute zero.
At absolute zero a substance has no kinetic energy
to give up.
Zero on the Kelvin scale corresponds to -273°C.
TEMPERATURE CONVERSION
FORMULAS
Celsius to Fahrenheit
Fahrenheit to Celsius
℃ = 𝐾 − 273
Celsius to Kelvin/ Kelvin to Celsius
Galileo’s gas thermometer became the
basis of liquid thermometers.
These liquid thermometers are based on
the principle of thermal expansion.
When a substance gets hotter, it
expands to a greater volume. Nearly
all substances exhibit this behavior of
thermal expansion. It is the basis of
the design and operation
of thermometers.
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LET’S SOLVE
1. 15
to
2. 12
to
3. 18
to K
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ACTIVITY!
1.A person with hypothermia has a body temperature
of 29.1°C. What is the body temperature in °F?
2.The normal temperature of a chickadee
105.8°F. What is that temperature in °C?
is
3.Liquid oxygen boils at normal pressure at -182.96 °C.
What is this temperature in Kelvin?
4.In many ideal gas problems, room temperature is 300
K to make calculations easier. What is this
temperature in Celsius?
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ACTIVITY!
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For listening
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