DASI-P - Energy & Interactions

What important physics idea is this question targeting?

The question targets the relationship between force fields and potential energy: when two objects exert non-contact forces on each other, they will increase in potential energy when they move in the direction opposite to the force they feel (and vice versa). (C)
The question targets the relationship between force fields and potential energy: that when an object feels a greater attractive force, that corresponds to having more potential energy, and when there are no forces there is no potential energy. (I)
This question targets student understanding of forces, energy and interactions. It’s asking them to think about how different kinds of forces result in different outcomes, and how that connects to core ideas in physics. (V)

Student A's response:

Which answer best describes what student A's response indicates about their physics understanding?

The student relates forces to energy, but does not do so in a consistent way. For example, they do not connect how an increasing force will mean the potential energy is increasing. (I)
The student has strong insights, and seems to grasp that forces can act without contact, but does not consistently connect this to the idea of fields storing potential energy. They treat the cart differently, implying that without a non-contact force at play, potential energy doesn’t apply — which is a good insight, albeit imprecisely articulated. (C)
The student understands that forces and energy relate to one another, but they need to explain their ideas more clearly. (V)

Which of the following options would best support Student B in being able to correctly respond to this question?

I would introduce a series of energy bar charts to help students track how energy is stored and transferred in each system. We’d focus especially on identifying cases where potential energy decreases and kinetic energy increases, using that pattern to highlight when a system involves stored energy in a field. This can help students move beyond everyday language like ‘it was forced’ and begin to see potential energy as tied to position within a field-based interaction. (C)
Students would benefit from seeing equations for how fields store energy and then calculating the result to determine whether PE is increasing, decreasing or constant for each case. They could then compare their answers with one another to resolve inconsistencies. (I/U)
I’d encourage Student A to think more critically about the underlying mechanisms at play. This question really pushes students to make connections across domains of motion and interaction. Helping them access that deeper layer of reasoning is the goal. (V)

Student B's response:

Which answer best describes what student B's response indicates about their physics understanding?

They seem to associate field-based interactions with potential energy, especially in the balloon/sweater case where they talk about energy being ‘created’ and stored for a ‘reaction.’ While not formally correct, this shows an intuitive sense that energy can be stored and later released when objects interact at a distance. (C)
The student has strong reasoning about how energy is created when you rub the balloon and creates electrostatic energy. And slowing down does help objects regain energy, like regenerative braking. I think the student is making good connections between movement and energy buildup, but they need help with vocabulary terms and equations for those terms. (I)
This student is thinking in terms of systems, and noticing how different components affect one another, and they’re considering energy in terms of interactions. It’s complex thinking, and close to having the right ideas. (V)

Which of the following options would best support Student B in being able to correctly respond to this question?

I would have groups act out the different systems (like magnets repelling, balls falling, or carts slowing), then pause to ask: ‘How does the motion change? Was energy being stored, released, constant or transferred?’ Then, we’d draw bar charts to represent the changes. This multimodal approach helps early learners link their observations to formal representations of energy. (C)
I’d ask the student to go back and reread the definition of potential energy from the textbook or their notes. Sometimes just reviewing the formal language helps clarify things. After that, I’d have them rewrite the definition in their own words to show they understand it and submit that as an exit ticket for the day. (I)
I’d encourage them to be more precise in their reasoning and attend closely to the details of each interaction, and then create a claim-evidence-reasoning table to better explain their ideas about energy. (V)