Centripetal Force Activity
Initial Publication Date: August 25, 2009
Summary
In this physics activity, students will simulate a race car on a circular track. Velocity, acceleration, and force vectors will be analyzed at various places along the track. As the students progress in the activity, prompts for student summaries with the teacher are given.
The students are accountable for discussing their findings and defending them using their knowledge and understanding of vectors. Eventually, students analyze changing speed around the track and also motion around an oval track. Students will gather their information in written form and orally with the instructor.
CollapseLearning Goals
Learning Objectives
1. Analyze the motion of a race car traveling at a constant speed around a circular track.
2. Draw velocity, acceleration, and force vectors.
3. Predict the motion of an object from given vectors.
Concepts
1. Vectors show the magnitude and direction of a property of an object.
2. An object in uniform circular motion has a constant speed with a changing velocity due to its change in direction.
3. The centripetal force acting on a object in uniform circular motion always acts perpendicular to its tangent velocity toward the center of the circle.
Vocabulary
1. vector
2. centripetal force
3. position
4. velocity
5. acceleration
1. Analyze the motion of a race car traveling at a constant speed around a circular track.
2. Draw velocity, acceleration, and force vectors.
3. Predict the motion of an object from given vectors.
Concepts
1. Vectors show the magnitude and direction of a property of an object.
2. An object in uniform circular motion has a constant speed with a changing velocity due to its change in direction.
3. The centripetal force acting on a object in uniform circular motion always acts perpendicular to its tangent velocity toward the center of the circle.
Vocabulary
1. vector
2. centripetal force
3. position
4. velocity
5. acceleration
Context for Use
This activity can be done during the Motion in Two Dimensions unit found in a typical physics curriculum. It can be completed in two periods of one block of time. Only large paper and markers are necessary, but having real match cars or remote control cars makes the activity more realistic. Students should already understand vectors and how they are added and subtracted. Since the materials needed are found in any school, this activity would be easy to perform in any physics classroom.
Description and Teaching Materials
This activity applies the student's knowledge of vectors for velocity, acceleration, and force to uniform circular motion. The introduction of this activity should take place after student's have had practice with vector addition and 2D motion. The materials needed for this activity are large pieces of paper and markers. Optional manipulatives are toy match cars and/remote control cars. Students need to understand speed, velocity, acceleration, and force prior to performing this activity. During the activity, students will follow directions which included drawing a race track and vectors at different places on the track. At various times, students will be instructed to discuss their finding with their teacher. Feedback will take place throughout the activity. The activity moves from uniform circular motion to accelerated circular motion to oval motion. Instructors can decide the capabilities of the students to find the appropriate stopping point. Students will complete answers to the given worksheet and turn in one per group. As a closure activity, student's will be asked to answer analysis questions.
Centripetal Force Activity Guide ( 30kB Aug25 09)
Centripetal Force Activity Guide ( 30kB Aug25 09)
Teaching Notes and Tips
One potential problem with this activity is the time needed for the teacher to check-in with each group. I would suggest 4 or 5 students to a group if the class is large. I would choose the groups for this activity by placing students of varying abilities together. Encourage students to be patient while waiting to talk with the teacher. You may find that students have the misconception of centrifugal force pulling outward. This activity should dispel the idea of any outward force, but it may take student's time to reconcile this concept. This activity is different from what I have done in the past in that student's discover how the vectors look to produce uniform circular motion, rather than being shown or told from a textbook. Hopefully, by seeing this motion on their own, student's will gain a better understanding of circular motion and how it works. Here are some additional web sites that I found useful for centripetal force lessons:
http://www.pbs.org/wgbh/nova/topgun/hotsciencetop/
http://regentsprep.org/Regents/physics/phys06/bcentrif/default.htm
http://www.pbs.org/wgbh/nova/topgun/hotsciencetop/
http://regentsprep.org/Regents/physics/phys06/bcentrif/default.htm
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Assessment
Students will be assessed in four ways:
1. The instructor will provide immediate feedback during the activity at predetermined
stopping points.
2. The activity sheet will be completed and handed in for evaluation.
3. The next day, some questions about centripetal force will be asked in an informal
quiz.
4. The final assessment will be answering similar types of questions on the unit test for 2D motion.
1. The instructor will provide immediate feedback during the activity at predetermined
stopping points.
2. The activity sheet will be completed and handed in for evaluation.
3. The next day, some questions about centripetal force will be asked in an informal
quiz.
4. The final assessment will be answering similar types of questions on the unit test for 2D motion.
Standards
9P.2.2.1.1
Use vectors and free-body diagrams to describe force, position, velocity and acceleration of objects in two-dimensional space.
9P.2.2.1.2 Apply Newton's three laws of motion to calculate and analyze the effect of forces and momentum on motion.
9P.2.2.2.2
Describe and calculate the change in velocity for objects when forces are applied perpendicular to the direction of motion.
Use vectors and free-body diagrams to describe force, position, velocity and acceleration of objects in two-dimensional space.
9P.2.2.1.2 Apply Newton's three laws of motion to calculate and analyze the effect of forces and momentum on motion.
9P.2.2.2.2
Describe and calculate the change in velocity for objects when forces are applied perpendicular to the direction of motion.