About

Misconception of Students

·       Objects slow down in the presence of friction or air resistance.

Outcomes of the simulator

·       Students can visualise how motion is affected when F_net > friction, when F_net = friction and when F_net < friction, while the cart remains in motion.

·       Students learn how to predict motion given the magnitude and direction of F_net with relation to the direction of motion.

 

Translations

Code	Language		Translator	Run

Credits

Tek Yong Shoun; lookang

Executive Summary:

These sources focus on the fundamental concepts of resultant force and its effect on the motion of an object under the influence of friction. The primary goal is to address the common student misconception that objects inherently slow down in the presence of friction or air resistance. The provided HTML5 simulator aims to help students visualize and understand how the relationship between the net force ((F_{net})) and friction determines an object's motion, including scenarios where an object continues to move even with friction present. The resources highlight the importance of considering the magnitude and direction of the net force relative to the direction of motion.

Main Themes and Important Ideas/Facts:

1. Addressing a Common Misconception:

• Both sources explicitly identify a prevalent student misconception: "Objects slow down in the presence of friction or air resistance." (Source 2)
• This misconception suggests that students may not fully grasp Newton's First Law (inertia) and the role of a net force in changing an object's state of motion.

2. The Role of the Simulator:

• The HTML5 simulator is designed as an interactive tool to counteract this misconception.
• Its primary function is to allow students to "visualise how motion is affected when Fnet > friction, when Fnet = friction and when Fnet < friction, while the cart remains in motion." (Source 2)
• This visualization is crucial for understanding that friction opposes motion but does not necessarily cause an object to stop immediately if a net force in the direction of motion exists or if the object is already in motion due to inertia.

3. Predicting Motion Based on Net Force and Friction:

• A key learning outcome of using the simulator is for students to "learn how to predict motion given the magnitude and direction of Fnet with relation to the direction of motion." (Source 2)
• This implies that students should be able to analyze a situation involving an applied force and friction and determine whether the object will accelerate, decelerate, or move at a constant velocity.

4. Examples and Analogies:

• The "About" section of the simulator page includes a link to a YouTube video by ETDtogo that explains the forward force produced by a simulation fan. This analogy uses a real-world example of a fire extinguisher cart moving left due to exhaust gases pushing right, illustrating Newton's Third Law and the concept of an applied force.

5. Pedagogical Intent:

• The inclusion of "Sample Learning Goals" and a section "For Teachers" indicates that this resource is specifically designed for educational purposes.
• The learning goals explicitly mention the desired solutions to the identified misconception through the use of the simulator.
• The "For Teachers" section (though currently containing "[texthttps://iwant2study.org/lookangejss/02_newtonianmechanics_3dynamics/ejss_model_Physics7/Physics7_Simulation.xhtml " frameborder="0"></iframe> (Source 2)
• The resource is part of the "Open Educational Resources / Open Source Physics @ Singapore" initiative, emphasizing its accessibility and potential for adaptation.

7. Credits and Licensing:

• Both sources credit Tek Yong Shoun and lookang as the authors/compilers.
• The content is released under a Creative Commons Attribution-Share Alike 4.0 Singapore License, promoting sharing and adaptation with proper attribution.
• Commercial use of the underlying EasyJavaScriptSimulations Library requires a separate license.

Quotes from Original Sources:

• (Source 2, Misconception of Students): "Objects slow down in the presence of friction or air resistance."
• (Source 2, Outcomes of the simulator - Solution1): "Students can visualise how motion is affected when (F_{net} \gt friction), when (F_{net} = friction) and when (F_{net} \lt friction), while the cart remains in motion."
• (Source 2, Outcomes of the simulator - Solution2): "Students learn how to predict motion given the magnitude and direction of (F_{net}) with relation to the direction of motion."
• (Source 2, Embed code): <iframe width="100%" height="100%" src="https://iwant2study.org/lookangejss/02_newtonianmechanics_3dynamics/ejss_model_Physics7/Physics7_Simulation.xhtml " frameborder="0"></iframe>

Conclusion:

These resources provide a valuable tool for educators to address a common misconception about friction and motion. The HTML5 simulator offers an interactive and visual way for students to explore the relationship between net force, friction, and an object's movement. By manipulating variables within the simulation, students can gain a deeper understanding of Newton's laws of motion in the presence of resistive forces. The open-source nature and clear learning goals make this a useful resource for physics education.

 

Study Guide: Resultant Force and Motion under Different Friction

Key Concepts:

• Force: A push or pull that can change the motion of an object. Measured in Newtons (N).
• Resultant Force (Fnet): The vector sum of all forces acting on an object. It determines the net effect of all forces on the object's motion.
• Friction: A force that opposes motion between surfaces in contact. It acts in the opposite direction to the intended or actual motion.
• Motion: A change in the position of an object over time. Can be described by its velocity (speed and direction).
• Newton's First Law (Law of Inertia): An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
• Newton's Second Law: The acceleration of an object is directly proportional to the net force acting on the object, is in the same direction as the net force, and is inversely proportional to the mass of the object (Fnet = ma).
• Newton's Third Law: For every action, there is an equal and opposite reaction.
• Visualisation of Motion: Understanding how different resultant forces affect an object's speed and direction while considering friction.
• Prediction of Motion: Being able to determine how an object will move based on the magnitudes and directions of the resultant force and friction relative to the object's current motion.

Study Questions:

1. Define force and provide the standard unit of measurement for force.
2. Explain the concept of resultant force. How is it determined when multiple forces are acting on an object?
3. Describe friction. In what direction does friction act relative to the motion of an object?
4. State Newton's First Law of Motion and explain its significance in understanding motion with and without friction.
5. State Newton's Second Law of Motion and explain how resultant force, mass, and acceleration are related.
6. How does Newton's Third Law relate to the demonstration involving the fire extinguisher cart moving to the left?
7. According to the source, what is a common misconception students have regarding objects moving with friction or air resistance?
8. Describe the three scenarios presented in the "Outcomes of the simulator" regarding the relationship between resultant force (Fnet) and friction, and how each scenario affects the motion of a cart.
9. Explain how the simulator can help students understand the relationship between the magnitude and direction of the resultant force and the prediction of motion.
10. What are some examples of interactive simulations provided in the source, besides the one focusing on resultant force and friction?

Quiz:

1. What is the resultant force? Explain its role in determining an object's motion according to Newton's Second Law.
2. Describe how friction affects the motion of an object. Explain why it is considered a force that opposes motion.
3. State the misconception students often have about objects moving with friction. How does the simulator aim to address this misconception?
4. Explain the scenario where the resultant force (Fnet) is greater than the friction acting on a moving cart. What happens to the cart's motion in this case?
5. Describe the situation when the resultant force (Fnet) is equal in magnitude and opposite in direction to the friction acting on a moving cart. What is the resulting motion?
6. What occurs when the resultant force (Fnet) acting on a moving cart is less than the friction opposing its motion, but still in the direction of motion? Explain the change in the cart's velocity.
7. How can the simulator help students visualize the interplay between resultant force and friction in different scenarios? Provide a specific example from the "Outcomes of the simulator."
8. Explain how understanding the direction of the resultant force relative to the direction of motion allows for the prediction of that motion.
9. According to the provided resources, what real-world demonstration illustrates Newton's Third Law of Motion related to forces and motion?
10. Briefly describe one other interactive simulation listed in the source material and its likely learning objective.

Answer Key:

1. The resultant force is the vector sum of all forces acting on an object. According to Newton's Second Law (Fnet = ma), the resultant force directly determines the acceleration of the object; a non-zero resultant force will cause the object to accelerate (change its velocity).
2. Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact. It acts in the direction opposite to the direction of the object's motion or the applied force causing the motion, thus slowing down or preventing movement.
3. A common misconception is that objects will always slow down and eventually stop in the presence of friction or air resistance, regardless of other forces. The simulator aims to show that an object can maintain motion even with friction if there is a net force in the direction of motion.
4. When the resultant force (Fnet) is greater than the friction acting on a moving cart and in the same direction as motion, the cart will experience a net force in the direction of its movement. According to Newton's Second Law, this will cause the cart to accelerate, meaning its speed will increase.
5. If the resultant force (Fnet) is equal in magnitude and opposite in direction to the friction acting on a moving cart, the net force acting on the cart is zero. According to Newton's First Law, the cart will continue to move at a constant velocity (constant speed and direction) as there is no unbalanced force to cause acceleration or deceleration.
6. When the resultant force (Fnet) acting on a moving cart is less than the friction opposing its motion but still in the direction of motion, there is a net force acting opposite to the direction of motion. This will cause the cart to decelerate, meaning its speed will decrease over time.
7. The simulator allows students to visualize how the cart's motion changes in different scenarios, such as when Fnet > friction (cart speeds up), Fnet = friction (cart moves at a constant velocity), and Fnet < friction (cart slows down), all while the cart remains in motion, directly addressing the misconception about objects always stopping due to friction.
8. If the resultant force is in the same direction as the motion, the object will speed up. If the resultant force is in the opposite direction to the motion, the object will slow down. If the resultant force is perpendicular to the motion (though not explicitly covered in detail here), it will change the direction of the velocity.
9. The YouTube video linked in the source, explaining why the simulation fan produces a forward force and relating it to the fire extinguisher cart moving left due to exhaust gases pushing right, illustrates Newton's Third Law (action-reaction pairs).
10. One other simulation is "Spinning Gyroscope JavaScript HTML5 Applet Simulation Model." Its likely learning objective is to allow students to interact with and understand the principles of angular momentum and stability related to spinning objects.

Essay Format Questions:

1. Discuss the importance of understanding resultant force in predicting the motion of objects, particularly in scenarios involving friction. Use examples from the provided resources to support your argument.
2. Explain how interactive simulations, such as the one described in the source, can be more effective than traditional methods in addressing common misconceptions about force and motion, specifically the misconception regarding friction and moving objects.
3. Analyze the relationship between Newton's Laws of Motion and the concepts of resultant force and friction. How do these laws provide a framework for understanding and predicting changes in an object's motion under various frictional conditions?
4. Describe the different possible relationships between the resultant force and friction acting on a moving object, and explain how each relationship affects the object's subsequent motion.
5. Based on the provided resources, discuss the role of open educational resources and interactive simulations in enhancing physics education and promoting a deeper understanding of fundamental concepts like force, friction, and motion.

Glossary of Key Terms:

• Acceleration: The rate at which the velocity of an object changes over time, in both speed and direction. Measured in meters per second squared (m/s²).
• Dynamics: The branch of mechanics concerned with the motion of objects under the action of forces.
• Inertia: The tendency of an object to resist changes in its state of motion. It is directly proportional to the object's mass.
• Magnitude: The size or extent of a quantity, usually represented by a numerical value and a unit.
• Net Force: Another term for resultant force; the overall force acting on an object.
• Open Educational Resources (OER): Teaching, learning, and research materials that are freely available for use, adaptation, and sharing.
• Simulator: A computer program that models a real-world system or phenomenon, allowing users to interact with it and observe its behavior under different conditions.
• Vector: A quantity that has both magnitude and direction. Force and velocity are examples of vector quantities.
• Velocity: The speed of an object in a particular direction. Measured in meters per second (m/s) with a specified direction.

Sample Learning Goals

Simulation to address Misconception of Students
M1: Objects slow down in the presence of friction or air resistance.
Outcomes of the simulator
Solution1: Students can visualise how motion is affected when $F_{net} \gt friction$, when $F_{net} = friction$ and when $F_{net} \lt friction$, while the cart remains in motion.
Solution2: Students learn how to predict motion given the magnitude and direction of $F_{net}$ with relation to the direction of motion.

For Teachers

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Research

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Video

 https://www.youtube.com/watch?v=vrgKspCxN4E by ETDtogo explains why the simulation fan produces a (point to the right) forward force. In the YouTube video, the cart moves to the left because the exhaust gases from the fire extinguisher pushes to the right.

 

 Newton's Third Law - Medicine Ball Experiment by ETDtogo

 

 Newton's Third Law - Water Rocket Experiment by ETDtogo

 Version:

1.  https://weelookang.blogspot.com/2018/11/resultant-force-and-motion-under.html 

Other Resources

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