This briefing document reviews information about an open-source HTML5 applet designed to simulate the behavior of stacking ring magnets. The applet, developed by Siti, Coco, Francisco Esquembre, and Felix J. Garcia Clemente, is hosted by Open Educational Resources / Open Source Physics @ Singapore. It aims to provide an interactive tool for primary school science education, allowing users to experiment with magnetic attraction and repulsion using ring magnets, wooden rings, and an iron ring in conjunction with a plastic rod. The simulation incorporates several physics concepts and addresses specific design challenges to enhance its educational value.

Main Themes and Important Ideas/Facts:

1. Purpose and Educational Goals:

• The primary purpose of the applet is to allow users, particularly primary school students, to explore the principles of magnetism through the interaction of stacking ring magnets.
• The simulation aims to demonstrate that "the rings will follow the law of magnetism, where the unlike poles will attract and the like poles repel."
• It also introduces non-magnetic rings (wooden and iron) to allow experimentation with their interaction with magnets.
• The applet is designed for users to "experiment with the arrangement" of the rings on a plastic rod.
• For teachers, the initial setup involves five rings placed on the left and a plastic rod on the right. Users can drag rings to a designated "release here" box, causing them to fall onto the rod.
• The top panel allows users to change the side (polarity) of the magnets.

2. Key Features and Functionality:

• Interactive Drag and Drop: Users can drag and drop rings onto a plastic rod. Variables like xMove, yMove, zMove, wMove, and iMove track when an object is being dragged.
• Magnetic Interaction: The simulation models magnetic attraction (unlike poles) and repulsion (like poles) between the ring magnets.
• Non-Magnetic Items: The simulation includes wooden and iron rings that do not exhibit magnetic attraction or repulsion in the same way as the magnet rings. The aim is that "Magnets dont feel any repelsion or attraction when blocked by Wooden Ring."
• Plastic Rod Constraint: A "barrier" is implemented to prevent users from dragging magnets inside the plastic rod. The aim is "No dragging of magnet inside the rod."
• Distance-Based Attraction: The attractive force between magnets "should consider distance."
• Mass-Dependent Repulsion: Repulsion between magnets "should include MASS," likely influencing the acceleration due to repulsion. The NumItemAbove() function is used in this calculation.
• Item Tracking: The simulation uses itemBelow() to "find the item behind a selected item," which is relevant for determining interactions in the stack.
• User Interface: The applet features a "release here" box and a top panel for changing magnet polarity.

3. Technical Aspects and Development:

• The applet is developed using HTML5 and Javascript, making it accessible through web browsers without the need for plugins.
• It is part of the Open Educational Resources / Open Source Physics @ Singapore initiative.
• The development involved addressing specific problems encountered during creation:
• "Error when item is dragged above 'Release area'."
• "Custom Prelim2 --> Error for falling of Wooden Ring FOLLOWED by Iron ring."
• "distance should not be shared across all items."
• "X Repelsion --> acceleration X."
• The applet was "Compiled with EJS 6.0 (191124)," indicating the use of the Easy Java/JavaScript Simulations Toolkit for its development. The license details for this toolkit are provided: "for commercial use of EasyJavaScriptSimulations Library, please read https://www.um.es/fem/EjsWiki/Main/EJSLicense and contact fem@um.es directly."

4. Authors and Credits:

• The applet is credited to: weelookang@gmail.com; Francisco Esquembre; Felix J. Garcia Clemente; Coco; Siti.
• Francisco Esquembre and Felix J. Garcia Clemente are also associated with the Easy Java/JavaScript Simulations Toolkit and Open Source Physics.

5. Related Resources:

• The page provides links to a YouTube video demonstrating the "Stacking Ring Magnets Virtual Lab for Primary School Science."
• It also lists numerous other interactive simulations and resources available from Open Educational Resources / Open Source Physics @ Singapore, covering various physics and mathematics topics relevant to different educational levels. This highlights the broader context of this applet within a larger collection of open educational tools.

Quotes from Sources:

• "The rings will follow the law of magnetism, where the unlike poles will attract and the like poles repel."
• "No dragging of magnet inside the rod."
• "Magnets dont feel any repelsion or attraction when blocked by Wooden Ring."
• "attractive power should consider distance"
• "repulsion should include MASS --> use NumItemAbove()"
• "find the item behind a selected item --> use itemBelow()"
• "Error when item is dragged above 'Release area'."
• "Custom Prelim2 --> Error for falling of Wooden Ring FOLLOWED by Iron ring"
• "distance should not be shared across all items."
• "X Repelsion --> acceleration X"
• "User can drag any of the rings into the 'release here' box. User is able to change the side of the magnets at the top panel. It will then fall into the plastic rod."

Conclusion:

The "Stacking Ring Magnets HTML5 Applet Javascript" is a valuable open educational resource designed to teach basic principles of magnetism to primary school students through an interactive simulation. It incorporates key concepts such as attraction, repulsion, the influence of distance and mass on magnetic forces, and the behavior of non-magnetic materials in a magnetic field. The applet's HTML5/Javascript foundation ensures broad accessibility, and its development has addressed specific design and technical challenges to provide a more robust and educationally sound experience. Its inclusion within the extensive Open Educational Resources / Open Source Physics @ Singapore platform further underscores its contribution to freely available science education tools.

Frequently Asked Questions: Stacking Ring Magnets Simulation

1. What is the purpose of the Stacking Ring Magnets HTML5 Applet? The primary purpose of this applet is to provide an interactive virtual laboratory for users, particularly primary school students, to explore the principles of magnetism through the manipulation of ring magnets, wooden rings, and an iron ring on a plastic rod. Users can observe how like poles of magnets repel and unlike poles attract, and how non-magnetic materials interact (or don't interact) with magnetic forces in a controlled environment.

2. How can I interact with the Stacking Ring Magnets simulation? Users can interact with the simulation by dragging the provided rings (magnets, wooden ring, iron ring) from the initial setup on the left and dropping them into the "release here" box, which then places them on the plastic rod on the right. For the magnet rings, users are also able to change the orientation (polarity) of the magnets using controls in the top panel before releasing them onto the rod.

3. What physical phenomena related to magnetism can be observed in this simulation? The simulation allows users to observe several key aspects of magnetism, including:

• Magnetic Attraction and Repulsion: Rings with opposite poles facing each other will attract and stack, while rings with like poles facing will repel, creating space between them.
• Interaction with Non-Magnetic Materials: The simulation demonstrates that wooden rings do not exert or experience magnetic forces, acting as spacers that do not block the magnetic interaction between magnets. Similarly, the iron ring's interaction with the magnets can be observed (though the specific nature of this interaction isn't detailed, it's implied it won't repel or attract when blocked by wood).
• Distance Dependence of Magnetic Force: The simulation aims to show that the attractive power between magnets is influenced by the distance separating them.
• Mass and Repulsion: The repulsive force between magnets is intended to consider the number of items above a given magnet, suggesting a relationship between mass (or perhaps the presence of other repelling magnets above) and the strength of repulsion.

4. What are the intended learning goals for users of this simulation? The sample learning goals suggest that users should be able to experiment with different arrangements of magnetic and non-magnetic rings and observe the resulting behaviors based on the laws of magnetism. This hands-on virtual experience helps students develop an intuitive understanding of magnetic forces and interactions.

5. Are there any limitations or intended constraints within the simulation? Yes, the developers aimed to implement certain constraints:

• Users are prevented from dragging magnets inside the plastic rod.
• Magnets are not supposed to feel repulsion or attraction when a wooden ring is positioned between them.
• There is a designated "Release area," and an error was noted if an item was dragged above this area.

6. What do the variables xMove, yMove, zMove, wMove, and iMove indicate? These variables are boolean indicators that track whether an object in the simulation is currently being dragged. They are set to true when an object is dragged and revert to false when the dragging action is released.

7. What do the functions NumItemAbove() and itemBelow() do within the simulation's code?

• NumItemAbove() is used to determine the number of items (presumably ring magnets) that are currently stacked above a selected magnet. This information is intended to be used in calculating the repulsive force, suggesting that repulsion increases with more magnets stacked above.
• itemBelow() is used to identify the item that is positioned directly underneath a selected item on the rod. This could be relevant for determining the immediate magnetic interactions between adjacent rings.

8. Who developed this Stacking Ring Magnets simulation and under what license is it released? The Stacking Ring Magnets HTML5 Applet was developed by weelookang@gmail.com, Francisco Esquembre, Felix J. Garcia Clemente, Coco, and Siti. It was compiled with EJS 6.0 and is released under a specified license (as mentioned in the second source, though the exact license name is not fully provided in the excerpts, it is noted as "a license"). The underlying EasyJavaScriptSimulations Library for commercial use has a separate license detailed at https://www.um.es/fem/EjsWiki/Main/EJSLicense, and inquiries should be directed to fem@um.es. The content itself is licensed under the Creative Commons Attribution-Share Alike 4.0 Singapore License.