Translations

Code	Language		Translator	Run

Credits

lookang

• Main Theme: This source focuses on a specific implementation of a pendulum wave effect using a JavaScript model simulation. It highlights its accessibility and educational purpose.
• Key Information:Title and Description: The title clearly identifies the content as a "Amazing Pendulum with Background Wave Effect JavaScript Model Simulation Applet HTML5." This indicates a digital simulation built with JavaScript and HTML5 technology, making it accessible through web browsers.
• Source and Context: It originates from "Open Educational Resources / Open Source Physics @ Singapore," emphasizing its role as an open educational resource for physics education.
• Breadcrumbs: The breadcrumbs ("Home," "Primary," "Secondary," "Dynamics," "Turning Effects of Forces," "Oscillations," "Junior College," "MolecularWorkbench," "EasyJavaScriptSimulation," "Android/iOS including handphones/Tablets/iPads," "Windows/MacOSX/Linux including Laptops/Desktops," "ChromeBook Laptops") provide context, suggesting the simulation is relevant for teaching oscillations across various educational levels and is built using Easy JavaScript Simulation, compatible with multiple devices and operating systems.
• Embed Option: The provision of an <iframe> code snippet demonstrates the intention for easy integration of the simulation into other webpages:
• <iframe width="100%" height="100%" src="https://iwant2study.org/lookangejss/02_newtonianmechanics_8oscillations/ejss_model_pendulum3Dwavewithbackground/pendulum3Dwavewithbackground_Simulation.xhtml " frameborder="0"></iframe>
• Credits: lookang is credited for this model. This aligns with the author mentioned in the first source.
• Related Resources: The page lists several external links under "Other Resources," pointing to various pendulum simulations and related physics education resources (e.g., GeoGebra, Walter Fendt, Phet Interactive Simulations, The Physics Aviary). This suggests a broader interest in and availability of similar educational tools.
• Version History: Links to previous versions of pendulum models by lookang are provided, indicating an iterative development process. One link is:
• "1. http://weelookang.blogspot.sg/2012/04/ejs-open-source-fifteen-uncoupled.html" "2. Ejs Open Source Fifteen uncoupled simple pendulums model"
• FAQ/Accordion: The presence of an accordion-style FAQ section (though the actual questions are generic login prompts and unrelated topics in the provided excerpt) suggests that the full webpage likely contains user support and information about the simulation.
• License Information: Similar to the first source, the webpage footer states: "Contents are licensed Creative Commons Attribution-Share Alike 4.0 Singapore License." This reinforces the open educational nature of the resource.

Key Themes and Important Ideas:

1. Demonstration of the Pendulum Wave Effect: Both sources directly refer to the "Amazing Pendulum Wave Effect," implying that the core subject is the visual and physical phenomenon where multiple pendulums of slightly different lengths appear to create wave-like patterns over time.
2. Educational Resource: The context of "Open Educational Resources / Open Source Physics @ Singapore" strongly indicates that the JavaScript model is designed for educational purposes, likely to help students visualize and understand the principles of oscillations and the unique behavior of coupled (or in this case, seemingly coupled through visual perception) pendulum systems.
3. Technology-Enabled Learning: The use of JavaScript and HTML5 highlights the role of technology in creating interactive and accessible learning tools for physics. The platform independence (Android/iOS, Windows/MacOSX/Linux, ChromeBook) further emphasizes this accessibility.
4. Open Source and Collaborative Nature: The Creative Commons license and the listing of credits (lookang) and related resources suggest a community-driven approach to developing and sharing educational materials. The reference to Easy JavaScript Simulation (EJS) also points to a specific open-source tool used in the creation.

Quotes:

• From Source 2 (Title): "Amazing Pendulum with Background Wave Effect JavaScript Model Simulation Applet HTML5" - This clearly states the nature and format of the resource.
• From Source 2 (Embed): The <iframe> code itself demonstrates how the resource is intended to be used and shared.
• From Source 2 (License): "Contents are licensed Creative Commons Attribution-Share Alike 4.0 Singapore License" - This specifies the terms of use and sharing.

Conclusion:

The provided sources highlight the existence of a digital simulation, created by lookang and hosted by Open Educational Resources / Open Source Physics @ Singapore, that demonstrates the "Amazing Pendulum Wave Effect." This simulation, built using JavaScript and HTML5, is intended as an open educational resource for teaching and learning about oscillations across various educational levels. Its platform independence and embeddable nature make it a versatile tool for educators. The Creative Commons licensing encourages sharing and adaptation for non-commercial purposes. Further exploration of the linked simulation would provide a deeper understanding of the specific features and pedagogical approach employed.

Study Guide: The Amazing Pendulum Wave Effect

Overview of the Phenomenon:

The "Amazing Pendulum Wave Effect" refers to a visually captivating demonstration where multiple pendulums, each with a slightly different period of oscillation, are released simultaneously. Due to these differing periods, the pendulums swing in and out of phase with each other, creating the illusion of waves traveling across the array. Over time, the pendulums will eventually return to their initial synchronized state, repeating the wave-like pattern.

Key Concepts:

• Pendulum: A weight suspended from a pivot point that swings freely under the influence of gravity.
• Period (T): The time it takes for one complete oscillation of a pendulum (one back-and-forth swing).
• Frequency (f): The number of oscillations per unit of time (usually measured in Hertz, Hz, where 1 Hz = 1 oscillation per second). Frequency is the inverse of the period (f = 1/T).
• Simple Harmonic Motion (SHM): An idealized form of periodic motion where the restoring force is directly proportional to the displacement and acts in the opposite direction. For small angles of displacement, a simple pendulum approximates SHM.
• Period of a Simple Pendulum: The period of a simple pendulum is primarily determined by its length (L) and the acceleration due to gravity (g), according to the formula: T = 2π√(L/g). Mass has a negligible effect on the period for small oscillations.
• Phase: The position within an oscillation cycle at a given point in time. Pendulums are "in phase" when they are at the same point in their swing cycle at the same time and "out of phase" when they are at different points.
• Superposition: The principle that when multiple waves or oscillations occur at the same time, the resulting displacement at any point is the vector sum of the displacements of the individual waves or oscillations. In the pendulum wave effect, the combined motion of the pendulums creates the visual wave patterns.
• Beat Frequency: When two oscillations with slightly different frequencies are superimposed, a phenomenon called "beats" occurs. The beat frequency is the difference between the two original frequencies and manifests as periodic variations in amplitude. In the pendulum wave effect, the changing relative phases create a similar visual "beating" pattern.

Simulation Aspects (from "Amazing Pendulum with Background Wave Effect JavaScript Model Simulation Applet HTML5"):

• JavaScript Model Simulation Applet HTML5: The resource highlights the use of a digital simulation, built with JavaScript and HTML5, to model and visualize the pendulum wave effect.
• Open Educational Resources / Open Source Physics @ Singapore: The simulation is identified as an open educational resource, suggesting it is freely available for educational purposes and potentially modifiable.
• Interactivity: The mention of "Applet HTML5" implies that the simulation is likely interactive, allowing users to manipulate parameters (such as pendulum lengths) and observe the resulting changes in the wave effect.
• Embeddable Model: The availability of an embed code (<iframe...>) indicates that the simulation can be easily integrated into web pages or other digital learning environments.
• Credits and Version Information: The resource acknowledges the creator (lookang) and provides links to related models and resources, suggesting a community and history of development.
• Diverse Learning Levels: The categorization under "Primary," "Secondary," and "Junior College" suggests the simulation is suitable for a range of educational levels, likely with adjustable complexity or focus.
• Integration with Other Resources: The inclusion of links to other physics simulations (e.g., from GeoGebra, Walter Fendt, PhET) indicates that the pendulum wave effect is a common topic in physics education and that various tools exist to explore it.

Quiz: Amazing Pendulum Wave Effect

Answer the following questions in 2-3 sentences each.

1. What is the fundamental reason why the "Amazing Pendulum Wave Effect" occurs when multiple pendulums are released?
2. Explain the relationship between the length of a simple pendulum and its period of oscillation. How does a change in length affect the period?
3. Define the terms "in phase" and "out of phase" in the context of oscillating pendulums. How do these concepts relate to the visual wave pattern?
4. What is the role of superposition in creating the visual "wave" observed in the pendulum wave effect?
5. The resource mentions a "JavaScript Model Simulation Applet HTML5." What are the potential benefits of using such a simulation to understand the pendulum wave effect?
6. Explain why the pendulum wave effect is a demonstration of oscillations rather than a continuous wave phenomenon like a water wave.
7. What does the fact that the pendulums eventually return to their synchronized starting positions tell us about the relationship between their individual periods?
8. Why is the mass of the pendulum bob generally considered negligible when calculating the period of a simple pendulum (for small oscillations)?
9. How is the concept of frequency related to the period of a pendulum's swing? Provide the mathematical relationship between them.
10. What might happen to the complexity and visual pattern of the "Amazing Pendulum Wave Effect" if the number of pendulums used in the demonstration is significantly increased?

Answer Key: Amazing Pendulum Wave Effect Quiz

1. The "Amazing Pendulum Wave Effect" occurs because each pendulum in the array has a slightly different length, resulting in a slightly different period of oscillation. These varying periods cause the pendulums to swing in and out of synchronization over time.
2. The period of a simple pendulum is directly proportional to the square root of its length. This means that a longer pendulum will have a longer period (it will swing more slowly), and a shorter pendulum will have a shorter period (it will swing more quickly).
3. Pendulums are "in phase" when they reach corresponding points in their swing cycle (e.g., their maximum displacement to the right) at the same time. They are "out of phase" when they reach corresponding points at different times, leading to the visual separation and wave-like appearance.
4. Superposition explains how the individual motions of all the pendulums combine to create the overall visual effect. At any given moment, the apparent "wave" is a result of the combined positions and velocities of each individual pendulum in the array.
5. Using a JavaScript simulation allows for interactive exploration of the pendulum wave effect by enabling users to change parameters like pendulum lengths or initial conditions. It provides a visual and dynamic representation that can enhance understanding compared to static descriptions or mathematical formulas.
6. The pendulum wave effect is a demonstration of oscillations because it involves a set of discrete, individual pendulums each undergoing its own periodic motion. Unlike a continuous wave, there is no medium through which a disturbance propagates; the wave-like pattern emerges from the collective behavior of independent oscillators.
7. The eventual return to a synchronized state indicates that the differences in the periods of the pendulums are precisely related, often as integer multiples or fractions over a common time interval. This allows for a cyclical pattern of synchronization and desynchronization.
8. For small oscillations, the restoring force (a component of gravity) is approximately proportional to the displacement from the equilibrium position, leading to simple harmonic motion. In this approximation, the mass cancels out in the derivation of the period formula, indicating it has a negligible effect.
9. Frequency (f) is the number of complete oscillations that occur in one unit of time, while the period (T) is the time taken for one complete oscillation. They are inversely related to each other, expressed by the formula: f = 1/T (or T = 1/f).
10. Increasing the number of pendulums, especially if the differences in their lengths (and thus periods) are carefully calibrated, would likely result in more complex and intricate visual wave patterns. The number of apparent "waves" and the duration of the complete cycle could also increase.

Essay Format Questions:

1. Discuss the physics principles underlying the "Amazing Pendulum Wave Effect," explaining how the concepts of period, frequency, and phase differences contribute to the observed phenomenon.
2. Analyze the educational value of using simulations, such as the "Amazing Pendulum with Background Wave Effect JavaScript Model Simulation Applet HTML5," for teaching and learning about oscillations and wave phenomena. Consider the benefits and limitations of such tools.
3. Explore the relationship between simple harmonic motion and the motion of a simple pendulum. Under what conditions does a pendulum exhibit approximate SHM, and how does this relate to the predictability of the pendulum wave effect?
4. Describe how the parameters of a pendulum (length, mass, initial displacement) affect its period of oscillation. Explain which parameters are most crucial in creating the "Amazing Pendulum Wave Effect" and why.
5. Compare and contrast the "Amazing Pendulum Wave Effect" with other examples of wave phenomena in physics, such as the superposition of sound waves or the behavior of waves on a string. Highlight the unique aspects of the pendulum wave demonstration.

Glossary of Key Terms:

• Amplitude: The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.
• Frequency (f): The number of complete cycles or oscillations that occur per unit of time, usually measured in Hertz (Hz).
• Oscillation: A repetitive variation, typically in time, of some measure about a central value or between two or more different states.
• Period (T): The time taken for one complete cycle of an oscillation or wave. It is the inverse of frequency (T = 1/f).
• Phase: The fraction of a cycle that has elapsed at a particular point in time, often expressed as an angle (in radians or degrees). It describes the position within an oscillation.
• Resonance: The tendency of a system to oscillate with greater amplitude at certain frequencies, known as the system's resonant frequencies.
• Restoring Force: A force that acts to bring a displaced system back towards its equilibrium position. In a pendulum, gravity provides the restoring force.
• Simple Harmonic Motion (SHM): A type of periodic motion where the restoring force is directly proportional to the displacement and acts in the direction opposite to that of displacement.
• Superposition Principle: The net displacement at any point due to two or more waves (or oscillations) is the algebraic sum of the displacements due to the individual waves at that point.
• Wavelength (λ): The spatial period of a periodic wave—the distance over which the wave's shape repeats. This concept is less directly applicable to the pendulum wave effect, which is more about temporal variations in phase.

Apps

 Video

Version

1. http://weelookang.blogspot.sg/2012/04/ejs-open-source-fifteen-uncoupled.html
2. Ejs Open Source Fifteen uncoupled simple pendulums model 
3. http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2428.0

Other Resources

1.  https://www.geogebra.org/m/sux2Q5ak The Conical Pendulum by ukukuku
2. http://www.walter-fendt.de/html5/phen/pendulum_en.htm 
3. http://physics.bu.edu/~duffy/HTML5/pendulum.html
4. https://phet.colorado.edu/en/simulation/pendulum-lab 
5. http://www.thephysicsaviary.com/Physics/Programs/Labs/PendulumLab/index.html