Physics 7A DL 2 Overview DL 2
Brief Overview
The first two Activities in this DL continue with the qualitative study of both the Three-Phase Model of
Matter and the Energy-Interaction Model. They extend the work you did on the FNTs assigned at the end
of DL 1. The last Activity begins Getting Quantitative with Models.
Activities
Activity 1.4: More Practice Using the Models
Purpose:
• To practice using the Three-Phase Model and the Energy-Interaction Model, and revisit the
meaning of the model constructs and the diagrammatic representations of the models.
• To become more familiar with applying these two models to particular thermal processes.
Learning Outcome:
• Be able to quickly and confidently apply both the Three-Phase Model and the Energy-
Interaction Model to the kinds of phenomena treated in this activity. This means being able to
confidently use the diagrammatic representations of both models to develop explanations and
answer specific questions related to these kinds of thermal phenomena.
Activity 1.5: Making Sense of the Heat Pack and other Phenomena
Purpose:
• To provide more practice making sense of a “strange phenomena” seen in the heat pack, by
applying the standard Three-Phase Model of Matter to some parts the heating and cooling
cycles of a heat pack.
• To extend/modify the Three-Phase Model of Matter to include super-cooling.
• To explain the “clicking process” of the heat pack and include it in the Three-Phase diagram
using the Energy-Interaction Model.
• To observe how this extension of the Three-Phase Model of Matter is an example of how
models start out simple and are then made more sophisticated as new data-patterns are
incorporated.
Learning Outcomes:
• Use the Three-Phase Model of Matter and the Energy-Interaction Model to explain the
behavior of a sodium acetate heat pack during each heating and cooling process of its entire
cycle.
Activity 1.6: Getting Quantitative
Purpose:
• To become familiar with constructs such as heat capacity, molar heat capacity, specific heat,
and heats of vaporization and melting.
• Relate these newly introduced constructs to the previously used constructs and ideas in the
Three-Phase Model of Matter and the Energy-Interaction Model.
Learning Outcomes:
• Be able to describe/explain the constructs of heat capacity, heat, and a change in temperature.
• Be able to describe/explain the connection between heat capacity and thermal energy.
• Be able to describe/explain the difference between heat capacity, molar heat capacity, and
specific heat and know how to decide when to use which one.
• Be able to describe/explain how ∆HVAP and ∆HMELT connect to ∆EBOND.
Unit 1: Applying Models to Thermal Phenomena DL 2
, Physics 7A Activity 1.4 DL 2
More Practice Using the Models
A) Basics of the Three-Phase Model:
Overview: Practice interpreting Temperature vs. Energy-Added diagrams
FNT 1:
1) Discuss with your group and make sure EVERY GROUP MEMBER is confident that they
can answer and explain parts a) and b) of the FNT.
2) For parts c) and d) of the FNT, you should have estimated the values close to those in the
box. Work out in your small groups any significant discrepancies you might have.
Your instructor will tell your group which prompt response to put on the board and explain to
the whole class.
Answers to FNT 1 c) and d):
i) liquid at ~350K; ii) completely solid at 273 K; iii) ~1/3 gas, ~2/3 liquid at 373 K
iv) initial conditions: all gas at 373 K, final conditions: liquid at ~50C; E ~-2470 kJ.
v) initial conditions: ~25% liquid at 0C, final conditions: gas at 100C; E ~ 3000kJ
Whole Class Discussion
B) Basics of the Energy-Interaction Model:
Overview: Using the Energy-Interaction Model to describe simple processes.
FNT 2:
1) Compare your responses for the processes in Activity 1.3, both the Temperature vs. Energy
added graphs and the Energy-Interaction diagrams.
2) Your instructor will tell you which one a) - g) to put on the board. Make sure the two
diagrams are consistent with each other and be ready to explain to the whole class.
Whole Class Discussion
Unit 1: Applying Models to Thermal Phenomena DL 2
Brief Overview
The first two Activities in this DL continue with the qualitative study of both the Three-Phase Model of
Matter and the Energy-Interaction Model. They extend the work you did on the FNTs assigned at the end
of DL 1. The last Activity begins Getting Quantitative with Models.
Activities
Activity 1.4: More Practice Using the Models
Purpose:
• To practice using the Three-Phase Model and the Energy-Interaction Model, and revisit the
meaning of the model constructs and the diagrammatic representations of the models.
• To become more familiar with applying these two models to particular thermal processes.
Learning Outcome:
• Be able to quickly and confidently apply both the Three-Phase Model and the Energy-
Interaction Model to the kinds of phenomena treated in this activity. This means being able to
confidently use the diagrammatic representations of both models to develop explanations and
answer specific questions related to these kinds of thermal phenomena.
Activity 1.5: Making Sense of the Heat Pack and other Phenomena
Purpose:
• To provide more practice making sense of a “strange phenomena” seen in the heat pack, by
applying the standard Three-Phase Model of Matter to some parts the heating and cooling
cycles of a heat pack.
• To extend/modify the Three-Phase Model of Matter to include super-cooling.
• To explain the “clicking process” of the heat pack and include it in the Three-Phase diagram
using the Energy-Interaction Model.
• To observe how this extension of the Three-Phase Model of Matter is an example of how
models start out simple and are then made more sophisticated as new data-patterns are
incorporated.
Learning Outcomes:
• Use the Three-Phase Model of Matter and the Energy-Interaction Model to explain the
behavior of a sodium acetate heat pack during each heating and cooling process of its entire
cycle.
Activity 1.6: Getting Quantitative
Purpose:
• To become familiar with constructs such as heat capacity, molar heat capacity, specific heat,
and heats of vaporization and melting.
• Relate these newly introduced constructs to the previously used constructs and ideas in the
Three-Phase Model of Matter and the Energy-Interaction Model.
Learning Outcomes:
• Be able to describe/explain the constructs of heat capacity, heat, and a change in temperature.
• Be able to describe/explain the connection between heat capacity and thermal energy.
• Be able to describe/explain the difference between heat capacity, molar heat capacity, and
specific heat and know how to decide when to use which one.
• Be able to describe/explain how ∆HVAP and ∆HMELT connect to ∆EBOND.
Unit 1: Applying Models to Thermal Phenomena DL 2
, Physics 7A Activity 1.4 DL 2
More Practice Using the Models
A) Basics of the Three-Phase Model:
Overview: Practice interpreting Temperature vs. Energy-Added diagrams
FNT 1:
1) Discuss with your group and make sure EVERY GROUP MEMBER is confident that they
can answer and explain parts a) and b) of the FNT.
2) For parts c) and d) of the FNT, you should have estimated the values close to those in the
box. Work out in your small groups any significant discrepancies you might have.
Your instructor will tell your group which prompt response to put on the board and explain to
the whole class.
Answers to FNT 1 c) and d):
i) liquid at ~350K; ii) completely solid at 273 K; iii) ~1/3 gas, ~2/3 liquid at 373 K
iv) initial conditions: all gas at 373 K, final conditions: liquid at ~50C; E ~-2470 kJ.
v) initial conditions: ~25% liquid at 0C, final conditions: gas at 100C; E ~ 3000kJ
Whole Class Discussion
B) Basics of the Energy-Interaction Model:
Overview: Using the Energy-Interaction Model to describe simple processes.
FNT 2:
1) Compare your responses for the processes in Activity 1.3, both the Temperature vs. Energy
added graphs and the Energy-Interaction diagrams.
2) Your instructor will tell you which one a) - g) to put on the board. Make sure the two
diagrams are consistent with each other and be ready to explain to the whole class.
Whole Class Discussion
Unit 1: Applying Models to Thermal Phenomena DL 2
