Materials:
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- 3 magnets (ring magnets work well)
- roll of toilet paper
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| Directions: |
- Experiment #1
- suspend the three magnets in one hand
- pull on lower magnet with the other hand (using a slow steady pressure).
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- Experiment #2
- suspend the three magnets in one hand
- pull on lower magnet with the other hand (using a quick pull).
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| Safety Concerns: |
- None.
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| Questions: |
- Do you see any difference in the magnets were pulled?
- What happens with a slow pull on the magnet?
- Why does a sharp jerk break the magnets differently?
- Which of the two breaks makes special use of the weight's inertia?
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| Concepts: |
- This is a demonstration of inertia. By pulling on the magnet slowly, we are putting a
strain on the lowest magnet. Due to the mass of the magnet, the strain above the weight is
much larger than below. The magnets break wherever the strain is highest. When a
sharp jerk is exerted on the magnet, the inertia of the weight keeps the strain below the
weight. Although there is some strain above the weight, compared to the strain below the
weight the strain in the latter is still higher, and the magnets below the weight.
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