Transcript What changes do I observe?

How Can Students in Grades 3-5
Understand Energy?
A Learning Progression Approach to
Understanding a Core Idea in Science
Presenters
• Sara Lacy
• Sally Crissman
TERC, Cambridge
TERC, Cambridge
Collaborators:
• Marianne Wiser,
• Roger Tobin
Clark University
Tufts University
What might a learning progression
approach for energy look like?
• A network of ideas that can develop over
time
• A scientific stance toward phenomena
that can develop progressively over time
and allow students to understand energy.
Why Start Learning about Energy
in 3rd Grade?
A scientific understanding of energy
What are the key ideas?
• The Nature and Forms of Energy
• Transfer and Transformation
• Dissipation
• Conservation
Some challenges to understanding
conservation of energy
1. Colloquial references to “conserving” energy appear to
contradict conservation of energy.
2. It appears that energy is simply gone when
– a ball stops bouncing
– a flashlight burns out
– hot water cools.
3. Many different units to quantify the same thing
The Teacher’s Perspective
Fulcrum Summer Energy Institute
for Science Teacher Leaders
Goal: Improved understanding of
1. The nature of energy
2. Conservation of energy
3. Conversion of thermal to mechanical/electrical
energy
Entry via Thermal Phenomena
Heat water using
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A hazelnut
A candle
Alcohol fuel
Electrical current from a battery run through a
resistor
• Mechanical energy from a frother
Children’s Ideas about energy
• Little experience thinking about everyday phenomena or
classroom activities in terms of energy transfer.
• “Where did the energy go?” - It’s GONE.
• A compressed spring does not have energy.
• Every object has either kinetic or potential energy.
• Batteries have energy.
How can children learn to look at phenomena in
terms of energy?
The Energy Lens
• What changes do I observe?
• How do those changes translate into energy changes?
• Where does the energy come from?
• Where did the energy go?
• Where is the dissipated
energy?
• Is all the energy
lost or gained by the system
accounted for?
The Energy Lens in Grade 3
What changes do I observe?
Change in speed, change in configuration
How do I describe what I’ve observed in terms of energy?
More speed - more energy of motion
The more stretched an elastic band, the more stored energy it
has.
Where did the energy come from?
Energy changes occur in PAIRS When the energy of an object increases,
energy of another object decreases.
A “Stepping Stone” for Energy Conservation:
Energy gains and losses occur in pairs. If one object or
system gains energy, one or more others lose energy.
Begin with transfer of energy from
one object to one other object
where both forms of energy are
the same and changes are
clearly visible
Progress to transfer of energy from
one object to one or more other
objects, or the environment, where the
forms of energy may be different and
may not be easily observed or
measured.
How can we represent energy?
Looking at Collisions
Through the Energy Lens
How can energy bars help students
understand energy transfer?
How can energy bars help students
understand energy transfer?
What sequence of activities can help
students understand “stored” energy?
The Energy Lens in 5th grade
• What physical changes do I observe?
• What are the indicators of energy change that I observe?
• What corresponding pairs of energy changes can I
identify? (If an object gains energy, what others lose
energy?)
• Where the heck did
the energy go?
(I can’t see it!)
Videos can help students describe
phenomena in terms of energy
How can the Energy Lens help us
understand energy gained as heat?
• What’s the energy story when the hand-crank
generator:
– Turns a propeller,
– Lights a light bulb,
– Charges a capacitor,
– Heats a resistor.
• What other ways can you heat a resistor?
– a battery
– a capacitor
– a hand-crank generator
Looking at heat transfer through the
Energy Lens
• What happens when cold water in a test tube is
immersed in a cup of hot water?
Questions
1. What are useful contexts to introduce energy
transfer?
—e.g., energy in life processes and in burning fuel
2. What tools can help students “see” energy
changes that are hard to observe?
—Videos
—Temperature probes
—”Energy meters” and video narration
—Particle magnifier
Other?
3. How can they learn to represent this abstract
entity?
Question
• Where can you use the energy lens in your
curriculum?