Transformation of Energy
Part 2: Heat Energy
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Key Learning:
Energy is all around us, comes in different forms, and
can change from one form to another.
Unit Essential Question:
How does energy move
from one object to another object?
Concept: The Flow of Energy Concept: Heat Energy
Concept: Waves
Lesson Essential
Lesson Essential
Lesson Essential Questions:
Questions:
Questions:
1.
How is kinetic
energy different from
gravitational potential
energy?
2.
How does energy
transfer and transform
from one object to
another?
3.
How can we trace
the flow of energy from
“beginning” to “end”?
1. How are heat
energy and
temperature
related?
2. What happens when
an object gains or
loses heat?
3. How do radiation,
conduction, and
convection transfer
heat from one place
to another?
1. How do waves carry
energy?
2. What types of energy
do waves carry?
3. How do mechanical
waves compare to
electromagnetic waves
Vocabulary
Vocabulary
Vocabulary
Energy
Heat Energy
Waves
Kinetic Energy
Temperature
Mechanical Waves
Gravitational Potential Energy
Particle Model
Transverse Waves
Energy Transfer
Conduction
Energy Transformation
Convection
Energy Chain
Radiation
Longitudinal Waves
Electromagnetic Waves
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WARM UPS
1. You’re riding your bicycle down the street and have to slam on the breaks. You see that
you left a black tire mark on the sidewalk. What type of energy transfer/transformation
is this evidence of? How do you know? (1 point)
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2. Think of an example where an increase in energy would cause the molecules of an object
to change (break apart, turn into something”new”, etc.). (You may notuse an ice cube or
wood rod!) (1 point)
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3. I have two cups of water. One is 10°C and the other is 100°C. Draw what the particles
look like in each cup. (2 points)
10°C
100°C
4. When cooking food on the stove using a pan, the food heats up even though it does not
touch the burner. How do you explain this? (1 point)
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Directions: Complete the following investigation. Answer all questions and parts of the
investigation to receive full credit. Remember the safety rules and how to be good
scientists. (20 Points)
INVESTIGATION #3: Smoke Signals
TRANSFORMING KINETIC ENERGY INTO HEAT ENERGY
GOALS:



In this investigation, you will …
Observe what happens when large quantities of kinetic energy are transformed into
heat energy, and this heat energy is concentrated in one part of an object.
Recognize that forces are not energy, they are the mechanism by which energy is
transferred in a system
Look at the role that forces play in the transfer of kinetic energy, and its
transformation into heat energy.
INVESTIGATION OVERVIEW:
A synopsis of this lesson is as follows…
This is the first, and possibly the most dramatic investigation of the heat energy
component of the TOE unit. By illustrating the transfer and the transformation of kinetic
energy into heat energy, this investigation bridges the investigations of the energy of
large moving objects (balls, cups, bottles, etc.) and the investigations of the kinetic energy
of particles, the heat energy. Distinguishing between the organized kinetic energy of the
moving rope and the random kinetic energy of the particles of the rope and wooden dowel
is the primary goal of this investigation. This distinction is made by looking at the
different effects that both types of energy have on the properties of the objects
involved.
There will be no variables, question, or hypothesis to complete.
The investigation relies on following procedure as well as
observation and application of scientific concepts
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Procedure
1. Gather a 1 meter length of rope and a large wooden dowel rod. Have one student
hold the large dowel rod in his hands with his arms outstretched. Have another
student wrap the rope around the dowel rod 1 time.
2. Using long strokes, pull the rope back-and-forth across the large wooden
dowel rod.
3. Make observations about the condition of the rope and of the wood. Record
your observations in your journal or notebook.
4. Repeat the procedure for all three pieces of rope.
5. Record your observations on the next page. (Observations should include
touch, sight, smell, sound at the very minimum)
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Observations
Directions: Record your observations in the chart below. (4 points)
Wood Dowel
Cotton Rope
(smaller white rope)
Nylon
(thicker, shiny
white rope)
Jute String
Analysis: (12 points total)
Directions: Complete the following questions about the investigation.
1.
Make an energy chain that describes the flow of energy in this activity. Be sure to
note each energy transfer and each energy transformation that takes place. It has been
started (not finished) for you. (8 points)
Chemical Potential Energy in food  transformed into  kinetic energy in arms 
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2.
You probably discovered that if the rope slides left and right along the length of
the dowel while you are pulling it forward and back, that it was difficult to get either the
wood or the ropes to begin to burn. Use the Particle Model to explain why it is important
to keep the rope sliding across the same spot on the dowel if you expect the dowel and
rope to get hot enough to start burning. (2 points)
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3.
When kinetic energy is transformed into heat energy, how does it affect the
molecules of an object? What evidence did you see from this investigation? (2 points)
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Conclusion
Directions: Write a concise summary of this investigation. Include the procedure, the
results, and answers to the following questions. (4 points)
 What happens when large amounts of kinetic energy gets transformed into heat
energy and delivered to a small area of an object (such as on the wooden dowel
 How is the heat energy in the rope different from the kinetic energy of the rope?
 Are all materials affected by heat energy the same?
 What role does the sliding friction force, between the rope and the wooden dowel
rod, play in this activity?
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Directions: Complete the following investigation. Answer all questions and parts of the
investigation to receive full credit. Remember the safety rules and how to be good
scientists. (35 Points)
Investigation #4: Heat Energy and Temperature:
THERE IS A DIFFERENCE!
GOALS:

In this lab investigation, you will …
Observe that there is a difference between the heat energy transferred to an
object and the change in temperature that results from this transfer of energy.

Learn how the mass of a substance influences how much its temperature will change
when it receives heat energy.

Learn that different substances respond differently when they absorb energy.
INVESTIGATION OVERVIEW:
A synopsis of this lesson is as follows…
Tea candles will be introduced as sources of heat energy. We will assume that the tea
candles burn identically. We will also assume that each of the tea candles burns uniformly,
so that it produces the same amount of heat energy each minute it burns. The first step
in the investigation is to make an energy chain describing where the heat energy produced
by the candle comes from. Then the class will divide into five groups. Two groups will use
candles to ‘heat up’ 100 grams of water, two other groups will ‘heat up’ 200 grams of
water, and the fifth group will ‘heat up’ 200 grams of sand. Groups that are working with
100 grams of water will separate and use either 2 or 4 candles to ‘heat up’ their water.
The groups working with 200 grams of water will divide up in the same way, and the group
working with the sand will use 4 candles. Each group will measure and record how the
temperature of their substance changes over a 6 minute period. The class will then share
their results and look for patterns in the results.
Question: (1 point)
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Manipulated Variables (what we change): ________________________
_________________________
_____________________________(1 point)
Responding Variable (what changes when we change the Independent Variable):
__________________________________________ (1 point)
My Hypothesis (an answer to the question we are asking):
______________________________________________________________
_______________________________________________________ (1 point)
Procedure
This is a ‘whole class’ investigation. The class will be divided into
several groups. Each group will make similar measurements, but will
investigate a different system than the other groups. After completing
the investigations, the groups will share their results with the class.
1.
Each group will need to gather 2 aluminum pans, 2 – 4 candles, 2 -4 wooden
blocks, 4 clothespins, and a timer. Look below to find out what materials and
the amounts your group will be using.
2.
Take one aluminum pan and place a clothespin on
each corner and invert it. This will serve as a
stand for the pan holding the water (or sand).
3.
Each group will need to measure out a specific amount of a substance and place
it in a second aluminum pan that will be placed on top of the stand created with
the first aluminum pan (see picture).
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4.
Stack your candles on the wood blocks and let Mr.
Herlihy know you are ready to have them lit. Place
your thermometer in the pan containing your
substance and record the initial temperature.
5.
Slide the aluminum pan over the lit candles. Start
the timer and record the temperature every
minute for 6 minutes.
Group #1 - Measure out 100 mL of water and pour it into the top aluminum pan. You
will be using 2 candles. (Remember, 100 mL of water has a mass of 100 grams)
Group #2 – Measure out 100 mL of water and pour it into the top aluminum pan. You
will need 4 candles. (Remember, 100 mL of water has a mass of 100 grams)
Group #3 - Measure out 200 mL of water and pour it into the top aluminum pan. You
will need 2 candles. (Remember, 200 mL of water has a mass of 200 grams)
Group #4 – Measure out 200 mL of water and pour it into the top aluminum pan. You
will need 4 candles. (Remember, 200 mL of water has a mass of 200 grams)
Group #5 – Measure out 200 grams of sand and pour it into the top aluminum pan.
Smooth the sand out so that it is evenly spread over the bottom. You will need 4
candles.
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Data Table: (12 points)
100ml Water
100ml Water
200ml
200ml
200g Sand
2 candles
4 candles
Water
Water
4 candles
(Group 1)
(Group 2)
2 candles
4 candles
(Group 5)
(Group 3)
(Group 4)
Initial
Temperature
(0 Minutes)
1 minute
2 minutes
3 minutes
4 minutes
5 minutes
6 minutes
Temp
(Final Temp. –
StartingTemp.)
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Graph: (10 points total)
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Analysis: (5 points total)
1. What determines the amount of heat energy transferred to the substances? (1 point)
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2. What factors determine the amount of the temperature increase in the substances?
(1 point)
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3. What happens when we increase the amount of substance in the heated pan? How do you
explain this change? (2 points)
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4. What happens when we increase the amount of heat energy transferred to the water?
Explain your reasoning using the Particle Model? (2 point)
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Conclusion
Directions: Write a concise summary of this investigation. Include the procedure, the
results, and how this investigation relates to our study of energy. (3 points)
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Directions: Complete the following investigation. Answer all questions and parts of the
investigation to receive full credit. Remember the safety rules and how to be good
scientists. (30 Points)
INVESTIGATION #5: Mixing and Melting
HEAT ENERGY & TEMPERATURE II
GOALS:

In this investigation, you will …
Predict and observe what happens to the final temperature of water when known
amounts of hot water are mixed with known amounts of cold water.

Use the data you collect and the Particle Model to build a better understanding of
heat energy and temperature.

Learn about and describe what is meant by thermal equilibrium.

Study the melting process by melting ice.
INVESTIGATION OVERVIEW:
A synopsis of this lesson is as follows…
The investigation begins with the review of heat energy and temperature changes
as viewed through the Particle Model. In this investigation, two samples of water having
different initial temperatures will be mixed together, and we will make predictions about
the outcome of the mixing process. In the previous investigation, heat energy was added
to the samples of water by burning candles. Here, there are no burning candles. All of the
heat energy is added to the water samples before they are mixed. We will see that the
final temperature of the mixed samples depends on their initial temperatures and their
masses. The concept of thermal equilibrium will be introduced to answer the question
“When is the mixing done?” Finally, we will mix hot water and ice to see if the solid water
(ice) at 0°C behaves differently from liquid water at 0°C.
There will be no variables, question, or hypothesis to
complete. This is a teacher demonstration and requires
students to complete data and questions after certain
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steps. Attention and observation are very important.
Case 1
Mixing equal amounts of hot water with cold water.
1. In this case, you will be mixing a sample of hot water with an equal sized sample of cold
water. (2 points)
100 mL of cold water in one small cup. Tcold =
100 mL of hot water in one small cup. Thot =
_____________ ºC
_____________ ºC
2. Before mixing the two samples together, check the prediction you think best describes
what will happen. (1 point)
o
o
o
(A) The final temperature of the mixture will be the temperature Tcold.
(B) The final temperature of the mixture will be closer to Tcold than to Thot.
(C) The final temperature of the mixture will be approximately halfway
between Tcold and Thot.
o
o
(D) The final temperature of the mixture will be closer to Thot than to Tcold.
(E) The final temperature of the mixture will be the temperature T hot.
Now try to estimate the final temperature of the mixed water samples:
Estimated final temperature, Tfinal = _______°C
3. The hot and cool samples will be mixed together into the large foam cup. They will be
stirred with a thermometer until the mixture is all at one temperature. This is called the
equilibrium temperature of the water mixture.
4. Measure and record this equilibrium temperature. (1 point)
200 mL of mixed water in large cup. Tfinal = _________ºC
5. Which water sample was the heat energy transferred FROM? (1 point)____________
6. Which water sample was the heat energy transferred TO? (1 point)_______________
7. How do you know which sample the heat energy was transferred TO and which sample
the heat energy was transferred FROM? (1 point)
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Case 2
Mixing hot water with twice as much cool water.
Part A – Different Amounts of Water
8. In this case, you will be mixing a sample of hot water into a larger sized sample of
cold water. (2 points)
200 mL of cold water in one small cup. Tcold =
100 mL of hot water in one small cup. Thot =
_____________ ºC
_____________ ºC
9. Before mixing the two samples together, check the prediction that you think best
describes what will happen. (1 point)
o
(A) The final temperature of the mixture will be closer to Tcold than to Thot.
o
(B) The final temperature of the mixture will be approximately halfway
between Tcold and Thot.
o
(C) The final temperature of the mixture will be closer to Thot than to Tcold.
Now try to estimate the equilibrium temperature of the mixed water samples:
Estimated equilibrium temperature, Tfinal = _______°C
10. The hot and cool samples will be mixed together pouring them both into the large
foam cup. They will be stirred with a thermometer until the mixture is all at one
temperature. Again, this is called the equilibrium temperature of the water mixture.
11. Measure and record this equilibrium temperature. (1 point)
200 mL cold and 100mL hot water mixture, Tfinal = _________ºC
12. Compare this equilibrium temperature with question #4. What do you notice about
them and why is this the case? (1 point)
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Part B – The Melting Process…Using Heat Energy to Change a Solid into a Liquid
13.
200 grams of ice (no liquid water) will be placed in the bowl. (1 point)
Record its temperature. Tice =
14.
_____________ ºC
100 mL of hot water will be placed in a small cup. (1 point)
Record its temperature. Thot =
_____________ ºC
15. Can you predict how many milliliters of hot water will be needed to completely melt
the ice? (None of our experiments thus far would help you make this prediction, so
this is really more of an educated guess.). (1 point)
My guess: ____________mL
16. 100 ml of hot water will be added to the ice until it is all melted. Record how many mL
of hot water must be added to melt all the ice. (3 points)
Record the equilibrium temperature after the first 100mL of water is added. _____ ºC
Amount of water needed to melt all the ice. ____________ mL
Record the equilibrium temperature after all the ice melts. _______ ºC
17. The ice and the cold water start at nearly the same temperature. Did the first
100mL of hot water have the same effect when added to the ice as it had when added to
the cold water? Explain your answer. (2 points)
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18. During class you hear two of your classmates discussing the investigation. How would
you respond to the following argument made by one of your classmates? “When the hot
water was mixed into the cold water, the cold in the cold water canceled the heat in the
hot water, and the mixture ended up warm.” (2 points)
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19. When an athlete injures her knee in competition, one of the first steps a coach will
take to treat the injury is to place an icepack on the injured knee. Describe the flow of
energy that takes place when the icepack is placed on the knee. Why insist on ice? Why
not use cold water? (2 points)
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20. Rubbing alcohol has a lower boiling temperature than water. If you place rubbing
alcohol on your bare arm, it will quickly evaporate and your skin will feel cool. Why does
your skin feel cool? Why can you easily smell the alcohol? (2 points)
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Conclusion
Directions: Write a concise summary of this investigation. Include the procedure, the
results, and answers to the following questions. (4 points)
 What happens when a cold object and a warm object are placed in contact with one
another?
 What factors determine the equilibrium temperature?
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Heat Energy Transfer
Directions: Complete the worksheet. The first part is seatwork and the second
part will go along with a demonstration. (20 points)
Part 1
Define each method of heat energy transfer and use the examples from the PowerPoint to
place them with the appropriate method of transfer in the “What I Think” column. Then,
write in the correct answers in the “What It Is” column. (3 points each row)
Method of Transfer/Definition
What I Think
Radiation
Conduction
Convection
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What It Is
Part 2
We will cook popcorn using all three methods of heat transfer. Write the method
of heat energy transfer under each picture and then give a brief description of
how it worked (cooked the popcorn). (3 points each)
Method of Heat Transfer: ________________
How did it cook the popcorn?
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Method of Heat Transfer: ________________
How did it cook the popcorn?
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Method of Heat Transfer: ________________
How did it cook the popcorn?
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List the three methods in order from fastest cooked to slowest cooked. (2 points)
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SUMMARIES
1. Rubbing your bare hands together creates friction, transforming kinetic energy into
heat energy. What is one way you could reduce the friction so that you did not transform
as much kinetic energy into heat energy? (1 point)
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Try it out… Were you right, did you reduce the amount of heat energy? (1 point)
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2. In the backyard of a house, there is a large pool, a kiddie pool, and a sandbox. The
sandbox and kiddie pool have the same amount of substance. List them in order of how
quickly they will heat up. Explain your reasoning. (2 points)
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3. How is heat energy transferred between two objects? (Circle One) (1 point)
a. Cold object to cold object
b. cold object to warm object
c. hot object to hotter object
d. warmer object to cooler object
4. This summary will be in the form of an assessment. Mr. Herlihy will give you a
description, directions, and guidelines for completing the assignment.
END OF PART 2!
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Notes
How to draw molecules in the Particle Model
Solid
Liquid
Gas
Vocabulary
Vocab Word
Definition
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