M

.pdf

School

University of Colorado, Boulder *

*We aren’t endorsed by this school

Course

1580

Subject

Physics

Date

Jan 9, 2024

Type

pdf

Pages

Uploaded by mikaylagj07

M.3: Better Model of Magnetism © 2023 PEER Physics Page 9 M.3 N ATURE OF S CIENCE R EADING Instructions: The purpose of this Nature of Science reading is to contextualize and formalize the Crosscutting Concepts and Science Practices from this activity. Physics principles (Disciplinary Core Ideas) were formalized in the Scientist’s Ideas reading. These three pieces– Crosscutting Concepts (CCCs), Science Practices (SEPs), and Disciplinary Core Ideas (DCIs) - are often referred to as “the Three Dimensions” of science learning. As you read, consider the ways you engaged in and with the three dimensions throughout this activity. M.3e CCCs – Making inferences using evidence from different scales: Interpreting patterns in evidence collected from different scales (for instance: macroscopic, microscopic, molecular, subatomic) allows scientists to make inferences about the properties of objects and make claims about cause-and-effect mechanisms. M.3f SEPs – Evaluating the impact of new data on scientific models: Scientists always interpret evidence from new experiments by applying the ideas currently present in their models. Sometimes, new data from previously unexplored scales can lead to major revisions in a scientist’s model for a phenomenon. Revising a model using new data improves the model is it can account for a wider range of situations. Testing and revising models requires scientists to conduct different kinds of experiments, where they make changes to one independent variable at a time and consider whether their model can account for the outcomes of those experiments. As part of this process, scientists commonly design experiments to identify patterns in evidence about a phenomenon at different scales. Developing explanations for these patterns and relating them to each other helps scientists to better visualize and understand the mechanisms that drive a phenomenon. In this activity, you tested and revised your model of magnetism to ensure it could explain a wider variety of observations. This process helps make your model more reliable and useful. Previous activities - developing your initial model of magnetism This activity - ensuring your model can account for a wider variety of observations Model had to account for: ▪ What is happening inside of the unrubbed nail before, during, and after it was rubbed with a magnet. ▪ Ferromagnetic materials can become magnetized. ▪ Cut pieces of magnetized nails have their own North and South magnetic poles. Model now also must account for: ▪ What is happening inside of the magnetized nail before, during, and after it was hit by a hammer. ▪ Magnetized objects can lose their magnetic properties. ▪ Characteristics of small-scale entities responsible for magnetic properties.

M.3: Better Model of Magnetism © 2023 PEER Physics Page 10 Identifying patterns in evidence about a phenomenon at different scales allows scientists to develop explanations about cause-and-effect relationships. In this activity, you made observations of how the magnetic properties of rubbed iron nails and test tubes filled with iron filings could be weakened - or even removed completely. Hitting the magnetized nails with a hammer affected their magnetic properties in a similar way to just shaking the test tube. Since both the test tube with iron filings and the iron nail could lose their magnetic properties, you were able to compare the two processes that led to this outcome and revise your model of magnetism to better explain what is happening within the iron nail. Your observations of the test tube with iron filings provided you with a visual analogy for what might be happening at a much smaller scale within the rubbed iron nail. You might have been surprised to see that the individual filings within the test tube did not need to move across the test tube for it to become magnetized. This observation provides insight into a small-scale mechanism that you had no way of visualizing before - that the magnetization of ferromagnetic objects can be explained due to the rotation, or alignment, of small entities within it. Your observations of the iron filings inside the test tube provided evidence to support claims about these entities and their properties within solid ferromagnetic objects, which in turn improves your model’s ability to account for all the observations you’ve made so far. Throughout this chapter, you have considered the merits and limitations of multiple different models of magnetism, including your own. You further refined your model of magnetism in this activity by comparing your observations of how a magnetized nail and an electrostatically charged straw interacted with different objects, like confetti and a compass needle. Since charged and magnetized objects interacted differently in your experiments, your evidence gave you a reason to think of the entities responsible for magnetism as being in some way different from those responsible for static and current electricity. By comparing your observations of objects affected by two different phenomena, you were able to claim that your model of magnetism required a new and unique kind of entity to fully explain all your observations - magnetic domains. By evaluating how different kinds of models try to account for the evidence you collected, you were able to continue revising and improving your own model of magnetism.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version