Physics 7A DL 6 Overview DL 6
Brief Overview
These activities provide more quantitative practice of applying the Energy-Interaction Model to
physical phenomena involving mechanical and thermal energies. You will also learn a graphing
method of depicting conservation of energy.
Activity 2.6 Follow-up of FNTs
Purpose:
• Practice relying on the logic of the model to think your way through to understanding and making
sense of very difficult/tricky physical phenomena.
• Practice applying the Energy-Interaction Model quantitatively to a variety of mostly mechanical
phenomena.
Learning Outcomes:
• Learn how to rely on the logic of the model to think your way through to understanding and
making sense of very difficult/tricky physical phenomena.
• Becoming confident that you can rapidly apply the Energy-Interaction Model to a variety of
phenomena similar to those in the set of FNTs
Activity 2.7 Graphically Representing Energy Relationships
Purpose:
• Provide practice working with the conservation of energy equation in the form of
𝐸𝑡𝑜𝑡𝑎𝑙 = 𝑃𝐸 + 𝐾𝐸 = 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
• Introduction to graphing energies as a function of the high parameter for vertical motion for
various definitions of y=0.
• Graphing energies for a spring-mass system.
Learning Outcomes:
• Realizing and understanding that 𝑃𝐸𝑔𝑟𝑎𝑣𝑖𝑡𝑦 depends on the choice of coordinate system, ie where
you set y=0.
• Understanding the graphical interpretation of a conservation of energy equation involving two
energy systems, one of which depends explicitly on the observable position.
• Understanding the constancy of the total energy and its graphical interpretation in a graph of two
energy systems, both plotted as a function of a position.
Activity 2.8 Sloppy/Intuitive Reasoning v. Precise Reasoning Using Models
Purpose:
• Provide practice applying the Energy-Interaction Model to a more complicated mechanical
system.
Learning Outcomes:
• Gain more confidence in using the Energy-Interaction model to analyze more complicated
mechanical systems.
• Gain more confidence in using the algebraic results obtained from application of the model to
gain insight into the physical situation.
Unit 2: Applying Models to Mechanical Phenomena DL 6
, Physics 7A Activity 2.6 DL 6
Follow-up of FNTs
Group 1
FNTs 1 and 2:
1) You should already have used the principle of energy conservation to develop an equation for the
change in height of a ball thrown straight up in the air (Activity 2.5, part B). Check with your
group for agreement on numerical answers to FNT 1.
2) Briefly summarize your solutions to FNT 2. Write a sentence or two explaining what fundamental
feature of the Energy-Interaction Model “accounts for” why changing the location of y = 0 does
not change your calculation of the ball’s maximum height above the floor. [Hint: think about the
general form of the algebraic expression of energy conservation.]
Group 2
FNT 3:
1) When you model the process described in FNT 3 in two different ways, i.e., using an interval
corresponding to the overall process versus splitting the overall process into two contiguous pieces
with separate intervals corresponding to each part, you should get the same result for the speed of
the ball at 4 m above the floor. Check your work with your group members.
2) In terms of the Energy-Interaction Model, why is it not necessary to divide the overall process
into two pieces in order to find the speed of the ball at 4 m above the floor falling down?
Group 3
FNT 4:
1) Construct Energy-Interaction diagrams for the two methods described in FNT 4. Use your
diagrams to explain how you know that an object thrown vertically upward will have the same
speed as it comes down through any point that it had going up through that same point.
2) Explain a scenario where the speed going up and down would not be the same for the same height.
Continue to Next Page
Unit 2: Applying Models to Mechanical Phenomena DL 6
Brief Overview
These activities provide more quantitative practice of applying the Energy-Interaction Model to
physical phenomena involving mechanical and thermal energies. You will also learn a graphing
method of depicting conservation of energy.
Activity 2.6 Follow-up of FNTs
Purpose:
• Practice relying on the logic of the model to think your way through to understanding and making
sense of very difficult/tricky physical phenomena.
• Practice applying the Energy-Interaction Model quantitatively to a variety of mostly mechanical
phenomena.
Learning Outcomes:
• Learn how to rely on the logic of the model to think your way through to understanding and
making sense of very difficult/tricky physical phenomena.
• Becoming confident that you can rapidly apply the Energy-Interaction Model to a variety of
phenomena similar to those in the set of FNTs
Activity 2.7 Graphically Representing Energy Relationships
Purpose:
• Provide practice working with the conservation of energy equation in the form of
𝐸𝑡𝑜𝑡𝑎𝑙 = 𝑃𝐸 + 𝐾𝐸 = 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
• Introduction to graphing energies as a function of the high parameter for vertical motion for
various definitions of y=0.
• Graphing energies for a spring-mass system.
Learning Outcomes:
• Realizing and understanding that 𝑃𝐸𝑔𝑟𝑎𝑣𝑖𝑡𝑦 depends on the choice of coordinate system, ie where
you set y=0.
• Understanding the graphical interpretation of a conservation of energy equation involving two
energy systems, one of which depends explicitly on the observable position.
• Understanding the constancy of the total energy and its graphical interpretation in a graph of two
energy systems, both plotted as a function of a position.
Activity 2.8 Sloppy/Intuitive Reasoning v. Precise Reasoning Using Models
Purpose:
• Provide practice applying the Energy-Interaction Model to a more complicated mechanical
system.
Learning Outcomes:
• Gain more confidence in using the Energy-Interaction model to analyze more complicated
mechanical systems.
• Gain more confidence in using the algebraic results obtained from application of the model to
gain insight into the physical situation.
Unit 2: Applying Models to Mechanical Phenomena DL 6
, Physics 7A Activity 2.6 DL 6
Follow-up of FNTs
Group 1
FNTs 1 and 2:
1) You should already have used the principle of energy conservation to develop an equation for the
change in height of a ball thrown straight up in the air (Activity 2.5, part B). Check with your
group for agreement on numerical answers to FNT 1.
2) Briefly summarize your solutions to FNT 2. Write a sentence or two explaining what fundamental
feature of the Energy-Interaction Model “accounts for” why changing the location of y = 0 does
not change your calculation of the ball’s maximum height above the floor. [Hint: think about the
general form of the algebraic expression of energy conservation.]
Group 2
FNT 3:
1) When you model the process described in FNT 3 in two different ways, i.e., using an interval
corresponding to the overall process versus splitting the overall process into two contiguous pieces
with separate intervals corresponding to each part, you should get the same result for the speed of
the ball at 4 m above the floor. Check your work with your group members.
2) In terms of the Energy-Interaction Model, why is it not necessary to divide the overall process
into two pieces in order to find the speed of the ball at 4 m above the floor falling down?
Group 3
FNT 4:
1) Construct Energy-Interaction diagrams for the two methods described in FNT 4. Use your
diagrams to explain how you know that an object thrown vertically upward will have the same
speed as it comes down through any point that it had going up through that same point.
2) Explain a scenario where the speed going up and down would not be the same for the same height.
Continue to Next Page
Unit 2: Applying Models to Mechanical Phenomena DL 6
