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http://weelookang.blogspot.com/2014/04/ejss-static-and-kinetic-friction-on.html

http://weelookang.blogspot.com/2014/04/ejss-static-and-kinetic-friction-on.html

picture from

iron

http://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Iron_disulfide_pyrite.jpg/320px-Iron_disulfide_pyrite.jpg

rubber

http://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Rubber_bands_-_Colors_-_Studio_photo_2011.jpg/320px-Rubber_bands_-_Colors_-_Studio_photo_2011.jpg

glass

http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Broken_glass.jpg/320px-Broken_glass.jpg

wood

http://upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Iroko_wood.jpg/320px-Iroko_wood.jpg

 

Translations

Code	Language		Translator	Run

Credits

This email address is being protected from spambots. You need JavaScript enabled to view it.; Francisco Esquembre

http://iwant2study.org/lookangejss/02_newtonianmechanics_3dynamics/ejss_model_frictionprimary/frictionprimary_Simulation.xhtml

Open Educational Resources / Open Source Physics @ Singapore hosts a collection of interactive JavaScript HTML5 applet simulation models for science and math education. The site features a model specifically on static and kinetic friction, suitable for primary school students, and embeddable in webpages. Numerous other simulations cover various topics, including Newtonian mechanics, kinematics, and electricity, targeting different grade levels and subjects. The resources are open-source and available under a Creative Commons license. Many were developed using Easy JavaScript Simulation (EJSS).

This briefing document reviews the provided source, "Static and Kinetic Frictional Model for Primary School Science Inquiry JavaScript HTML5 Applet Simulation Model - Open Educational Resources / Open Source Physics @ Singapore | Open Educational Resources / Open Source Physics @ Singapore," focusing on its main themes and key information.

Main Theme: This source describes an interactive JavaScript HTML5 applet simulation model designed for primary school science inquiry into the concepts of static and kinetic friction. It is an Open Educational Resource (OER) developed by Open Source Physics @ Singapore.

Key Information:

• Educational Focus: The simulation aims to teach primary school students about static and kinetic friction through an engaging and interactive experience.
• Technical Details: The simulation is built using JavaScript HTML5 and is compatible with various devices including desktops (Windows, MacOSX, Linux), laptops (Chromebooks), and mobile devices (Android, iOS).
• Accessibility: The simulation is embedded on a webpage using an iframe, allowing easy integration into various learning platforms and websites. The source code and translations are available, promoting open access and collaboration.
• Supporting Resources: The page provides links to an introductory blog post with further explanations and images of different materials (iron, rubber, glass, wood) which likely feature in the simulation.
• Credits: The simulation was developed by "lookang" in collaboration with Francisco Esquembre, a key contributor to the Easy Java/JavaScript Simulations (EJS) project.

Quotes:

• Embed this model in a webpage: <iframe width="100%" height="100%" src="https://iwant2study.org/lookangejss/02_newtonianmechanics_3dynamics/ejss_model_frictionprimary/frictionprimary_Simulation.xhtml " frameborder="0"></iframe>

Overall, this source highlights the development and availability of an interactive, open-source educational resource for teaching fundamental physics concepts to young learners. It emphasizes accessibility, providing clear instructions for embedding the simulation and links to additional information. The resource underscores the commitment of Open Source Physics @ Singapore to creating engaging learning tools for science education.

 

Exploring Static and Kinetic Friction: A Study Guide

Short Answer Questions

1. What is the key difference between static and kinetic friction?
2. Describe how the coefficient of friction relates to the surfaces in contact.
3. Provide a real-world example where understanding static friction is crucial.
4. Explain the concept of a "threshold force" in the context of static friction.
5. How does the applied force affect the frictional force when an object is at rest?
6. Why does kinetic friction generally have a lower value than static friction?
7. How would the simulation model behave if the surfaces were perfectly smooth (frictionless)?
8. Name two factors that can affect the coefficient of friction between two surfaces.
9. Explain why it's easier to keep an object moving at a constant velocity than it is to start it moving from rest.
10. Give an example of how lubrication can be used to reduce friction.

Short Answer Key

1. Static friction acts on objects at rest, preventing them from moving, while kinetic friction acts on moving objects, opposing their motion.
2. The coefficient of friction is a value that represents the roughness between two surfaces. A higher coefficient indicates greater roughness and, therefore, more friction.
3. Designing the tires of a car requires an understanding of static friction to ensure sufficient grip on the road to prevent skidding.
4. The threshold force is the minimum force required to overcome static friction and initiate motion. Once this force is exceeded, the object starts to move.
5. When an object is at rest, the static frictional force increases proportionally to the applied force until the threshold force is reached.
6. Kinetic friction is generally lower than static friction because fewer molecular interactions occur between the surfaces when they are in motion.
7. If the surfaces were perfectly smooth, there would be no friction. The object in the simulation would move indefinitely at a constant velocity with the slightest applied force.
8. Factors affecting the coefficient of friction include the type of materials in contact and the roughness of their surfaces.
9. It's easier to keep an object moving because kinetic friction is generally lower than static friction. Therefore, less force is required to maintain constant velocity.
10. Applying oil to a door hinge reduces friction by creating a thin layer between the surfaces, allowing them to slide more easily.

Essay Questions

1. Discuss the relationship between the applied force, frictional force, and the motion of an object. Explain how these concepts are related to Newton's Laws of Motion.
2. Compare and contrast static and kinetic friction. Analyze how the coefficients of static and kinetic friction influence the behavior of objects in different scenarios.
3. Critically evaluate the limitations of the static and kinetic frictional model. Discuss potential real-world factors that the simplified model might not account for.
4. Using examples from the simulation model, explain how different materials and surface properties can affect the magnitude of frictional forces.
5. Discuss the importance of understanding friction in various engineering applications. Provide specific examples and explain how engineers manipulate friction to achieve desired outcomes.

Glossary of Key Terms

1. Friction: A force that opposes the motion of surfaces in contact.
2. Static Friction: The friction that prevents an object at rest from moving.
3. Kinetic Friction: The friction that acts on a moving object, opposing its motion.
4. Coefficient of Friction: A numerical value representing the roughness between two surfaces; a higher value indicates greater friction.
5. Threshold Force: The minimum force required to overcome static friction and start an object moving.
6. Applied Force: The force exerted on an object.
7. Normal Force: The force exerted by a surface that supports the weight of an object resting on it.
8. Lubrication: The process of reducing friction between surfaces by introducing a substance (like oil) that allows them to slide more easily.
9. Simulation Model: A computer program that imitates a real-world phenomenon to understand its behavior.
10. Newton's Laws of Motion: Fundamental principles that describe the relationship between force, mass, and motion.

11. Video

12. https://notebooklm.google.com/notebook/dc8e3b50-a703-4fb9-954b-cf83009daab5/audio

Friction FAQ

What is friction?

Friction is a force that opposes motion between two surfaces in contact. It occurs because of the microscopic irregularities on the surfaces that interlock and resist sliding.

What are the two main types of friction?

There are two main types of friction:

• Static friction: The force that prevents an object from moving when a force is applied to it.
• Kinetic friction: The force that opposes the motion of an object that is already moving.

Which is stronger: static or kinetic friction?

Static friction is generally stronger than kinetic friction. This is why it takes more force to start an object moving than to keep it moving.

What factors affect the amount of friction?

Several factors affect the amount of friction:

• The types of surfaces in contact: Rougher surfaces have more friction than smooth surfaces.
• The force pressing the surfaces together: The greater the force pressing the surfaces together, the greater the friction.
• The relative speed of the surfaces: Kinetic friction generally increases with the relative speed of the surfaces.

How is friction useful in everyday life?

Friction is essential for many everyday activities, including:

• Walking: Friction between your shoes and the ground allows you to push off and move forward.
• Driving: Friction between the tires of a car and the road allows the car to accelerate, brake, and turn.
• Writing: Friction between a pen or pencil and paper allows you to make marks.

How can friction be reduced?

Friction can be reduced by:

• Using lubricants: Lubricants, such as oil or grease, create a thin layer between surfaces, reducing friction.
• Using smooth surfaces: Smoother surfaces have less friction than rough surfaces.
• Using rollers or wheels: Rollers and wheels reduce friction by replacing sliding motion with rolling motion.

What is the role of friction in the simulation model?

The simulation model allows you to explore the effects of different surfaces and applied forces on static and kinetic friction. You can change the surface materials and the applied force to see how these factors affect the amount of friction.

How can I access the simulation model?

You can access the simulation model by clicking on the "Embed" link provided on the source website. This will open the simulation in your web browser.