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Starting Point-Teaching Entry Level Geoscience > Teaching with Data > Browse Examples > Measuring the coefficient of friction of a skater on ice
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Measuring the coefficient of friction of a skater on ice

Peter Bohacek, Henry Sibley High School
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This material was originally developed through comPADRE
as part of its collaboration with the SERC Pedagogic Service.

Summary

Students use a video clip of a gliding ice skater to determine the coefficient of friction of the skater on ice. Vernier LoggerPro's video analysis tools are used to plot the velocity vs time. From the slope of this line, students can determine the acceleration and use Newton's Second Law to calculate the coefficient of sliding friction between the skates and the ice.

Learning Goals


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A video clip of kids gliding across ice contains all the information needed to determine to coefficient of friction between skates and ice.
Students learn that they can extract sufficient data from a simple video clip of a skater gliding across ice to determine the coefficient of sliding friction. This type of activity is a departure from conventional textbook questions where all the required quantities are provided explicitly.

Students also practice video analysis skills, graphing, data interpretation, and Newtonian mechanics.


Context for Use

This activity is appropriate for use in an introductory physics course, either high school or college level. It is best used with students who have some experience using Vernier's LoggerPro video analysis tools. The student handout provides step-by-step instructions, but the exercise could also be presented as an open-ended activity.

Teaching Materials

Outline of activity:
  1. Students download one of the six videos provided below.
  2. Students import the video into LoggerPro, use the video analysis tools to capture frame-by-frame data of the skater's motion.
  3. Next, students plot the horizontal velocity vs time for the skater during the period that the skater is gliding. The slope of this graph shows the acceleration -- the rate at which the skater is slowing due to the force for friction of the ice on the skates.
  4. Then, students use Newton's second Law along with the definition of the coefficient of friction to develop a relationship between the acceleration of an object being slowed by friction and the coefficient of friction.
  5. Finally student use this relationship and the acceleration from their graph to calculate the coefficient of friction between the skates and the ice.

Materials:

  1. Mari glides to the right ice skating video 1 (Quicktime Video 883kB Aug19 10)
  2. Mari glides to the left ice skating video 2 (Quicktime Video 870kB Aug19 10)
  3. Siri glides to the right ice skating video 3 (Quicktime Video 811kB Aug19 10)
  4. Siri glides to the left ice skating video 4 (Quicktime Video 865kB Aug19 10)
  5. Carl glides to the right ice skating video 5 (Quicktime Video 772kB Aug19 10)
  6. Carl glides to the left ice skating video 6 (Quicktime Video 763kB Aug19 10)

Teaching Notes and Tips

Assessment

Possible assessments include:

References and Resources

Vernier (more info) , manufacturer of LoggerPro data analysis software
Instructions on doing video analysis using LoggerPro (pdf file)
A description of a similar problem. In the problem shown, we find the maximum acceleration for a car on a surface with a given coefficient of friction. In the activity described here, we use the acceleration to calculate the coefficient of friction.


Subject

Physics:Classical Mechanics:Applications of Newton's Laws, Newton's Second Law, Motion in One Dimension

Grade Level

College Lower (13-14), High School (9-12)

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