Transcript AIM: What is Heat?

Mr. Z’s
Introduction to HEAT unit
AIM: What is Heat?
Recognize that Heat
is a form of Energy
AIM: What is Heat?
Heat, temperature, thermal energy,
analogy
AIM: What is heat?
What were the forms of energy again?
Heat (thermal), light, sound, electric, nuclear,
chemical, magnetic, mechanical
AIM: What is heat?
So can heat actually do work?
What is this called?
AIM: What is heat?
Watch this Demo!
How does this happen?
The heat from the light bulb
cause the air movement.
What makes a pinwheel move?
Moving air.
AIM: What is heat?
So, just what is heat?
It’s really a COMPLEX issue.
Let’s examine some of its parts!
AIM: What is heat?
What are the three phases of matter again?
IN which phase do the particles move the most?
So, which phase would contain the most energy?
Energy of motion is called what again?
(Kinetic Energy)
AIM: What is heat?
What is temperature?
DEFINITION: Temperature is the measure of
AVERAGE kinetic energy of a substance
The faster the particles in a substance move, the
more kinetic energy they have, the higher their
temperature
AIM: What is heat?
DEFINITION: Temperature is the measure of
AVERAGE kinetic energy in a substance (of its
particles).
IN which phase of matter, do the particles
vibrate and move the fastest?
Gas.
AIM: What is heat?
Are gases usually hotter then liquids or solids?
Is steam usually hotter then water or ice?
Why?
Cause its particles are moving (vibrating) faster!
Cause it has more kinetic energy!
AIM: What is heat?
Watch this Demo!
FACT: Any time you have two samples of the
same substance, the one which is “hotter” …
has more kinetic energy.
Its particles are moving faster … which is what
is causing it to be warmer.
AIM: What is heat?
Watch this Demo!
Beaker of Hot Water, Beaker of Cold Water, Food Dye
In which Beaker does the food dye spread quicker?
Why?
AIM: What is heat?
What is the difference between the TERMS:
Temperature and Thermal Energy?
Temperature is defined as ...
The average kinetic energy in a substance
Thermal Energy is defined as
the TOTAL kinetic energy in a substance.
AIM: What is heat?
Thermal Energy is the TOTAL kinetic energy
and not the average. What does that mean?
Here’s a group of numbers:
4, 6, 8, 3, 5
What is the AVEARAGE of these numbers?
What is the TOTAL of these numbers?
Do you see the analogy?
AIM: What is heat?
What are these two objects?
AIM: What is heat?
EXAMPLES:
At what temperature does water boil?
Does a boiling cup of water have the same
temperature as a pot of boiling water?
So, is their average temperature still the same?
Of course. Its 100 degrees C
AIM: What is heat?
Which would hurt you more if it spilled on you?
A cup of boiling water, or a pot of boiling water?
Why?
The Bucket of Boiling has more total energy.
It has MORE thermal energy.
AIM: What is heat?
DEFINITION OF HEAT:
Heat only moves in one direction!
Heat is the movement of thermal energy from an
area (or substance) of higher temperature to an
area (or substance) of a lower temperature.
Heat is thermal energy moving from a warmer
object to a cooler object
AIM: What is heat?
When you put a hot roast beef in the
fridge
Does the cold air of the fridge cool
the Roast Beef?
Or does the roast beef loose its heat
to the fridge?
AIM: What is heat?
When you put a water in the freezer?
How does it turn to ice?
It looses its heat till it freezes
AIM: What is heat?
What are the Three Temperature Scales?
Kelvin, Celsius, Fahrenheit
At 0 degrees Kelvin, there is no kinetic energy.
So, if there is no kinetic energy, are any particles
moving at 0 degrees Kelvin
That is why its called Absolute Zero
AIM: What is heat?
AIM: What is heat?
Homework:
INTERNET QUESTIONS