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UM A4 Video Clip 1: Group 3 answers Initial Ideas questions
Group 3 talks about the Initial Ideas questions and shows how students can often confound magnetic and static electric effects. Initially it seems they think only certain metals can be picked up by a magnet. But then they go on to discuss picking up small pieces of paper with a balloon as being a magnetic effect. They decide that only materials that have a 'magnetic charge' are affected and that not all metals have such a charge! They agree quickly on how the poles of two magnets would interact but decide to represent this using + and - symbols more usually used for electrical charges. The end of the clip shows the representation they drew on a whiteboard for the class discussion.
UM A4 Video Clip 2: Group 3 tests some materials
Group 3 tests some materials for Step 1 and discusses Step 2 of Exploration #1. Prior to the clip they had tested several non-metals and found no reaction. They then test aluminum and also find no reaction. It seems that Anna is particularly worried about this result; she whispers that she thinks something should be happening and repeating the test several times. They then find that a steel nail (off camera) and a metal bead both attract a magnet. Karen suggests that the bead must also be steel but eventually they discover it is actually nickel. When discussing how to answer the question in Step 2 Anna still seems to be concerned that not all metals interacted with the magnet.
UM A4 Video Clip 3: Group 9 tests two magnetized nails
Group 9 predicts and then conducts the tests in Step 4 of Exploration #2. In Step 3 they had tested an unmagnetized nail with a magnetized nail. While they were doing this they overheard a neighboring group (who were already working on Step 4) talking about 'repelling' and were confused because they only saw attraction. As they predict what will happen with two magnetized nails they realize the source of their confusion and predict that they will see repulsion from both ends. When they conduct the investigation they see that their prediction was not correct but do not seem too concerned. Finally Bailey suggests that rubbing the nail has turned it into a magnet.
UM A4 Video Clip 4: Orientation of a floating magnetized nail
Group 3 floats a magnetized nail in Step 1 of Exploration #3 to see if it has a preferred orientation. They decide that the head end of their nail always points toward the clock in the room (which is approximately north). After asking some other groups Niki reports that some point north and some south. The clip ends with Group 9 being asked about their results by Becky (Group 8). Becky is surprised that they got something different; but at the end Bailey suggests that it depends on which end of the magnet was used to rub the nail.
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UM A4 Video Clip 5: Class discussion of Summarizing Question S3
The instructor reviews the results of a clicker question vote on S3. Almost all the class agrees that whatever it is that causes a nail to become magnetized is inside the nail; a small number say it is on the surface. He then calls on some groups to give their reasoning. Group 5 (Chris - off camera) says it is inside based on the observations that after both touching the nail and immersing it in water it retained its magnetic properties. Group 3 turns out to be the dissenting group based on their perception that after immersing in water the magnetic strength seemed weaker. Group 7 (Mary) then agrees with Group 5 and Mary gives a hint at a fledgling model involving moving something around inside the nail. The instructor then uses this to guide the class into thinking about their initial models.
UM A4 Video Clip 1: Group 3 answers Initial Ideas questions