Schottenbauer Publishing

Wednesday, October 14, 2015

Friction & Motion

Friction, which slows motion, is almost everywhere! One of the few exceptions is an air hockey table, which reduces friction significantly by using air. Even on an air hockey table, friction eventually wins and motion stops.

The following graph, excerpted from Gravity, Springs, & Collisions: Volume 2 from Schottenbauer Publishing, shows a disk traveling on an air hockey table.

Discussion Questions
  1. How many collisions occur in the graph?
  2. Draw a sketch of the air hockey table, showing the points of collision with sides of the table. Label each point of collision with the time. Number each segment of the journey.
  3. Make a table, listing each segment in one column. In the next column, describe whether the effects of friction are present (yes/no).
  4. How many collisions occur before the effects of friction are apparent?
  5. Calculate the average speed of the puck during each segment. Add these to the table from #3. 
  6. Calculate the initial kinetic energy of the puck. The air hockey puck has mass of 1.22 g, diameter 3.2 cm, and height 0.2 cm.
  7. In the final segment, what is the average kinetic energy of the puck?
  8. Why does the puck eventually stop? Draw a diagram of the side of the puck, showing theoretical initial and final conditions.

Over 8,000 graphs from Schottenbauer Publishing provide additional real-life topics for student learning, including sports, transportation, construction, environment, music, entertainment/toys, and general physics. 

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