Bottle Rockets, Teacups and the Real World: A senior seminar to bridge the gap between physics stude

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Bottle Rockets, Teacups and the Real World A
senior seminar to bridge the gap between physics
student and life after college

• William T. Franz
• Randolph-Macon College
• CSAAPT, March 25, 2006

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Goals of the Senior Seminar

• Bridge to the real world from the world of
  coursework.
• Communication skills written and oral.
• Formal and informal presentation, including
  teaching.
• Integration of course material practical
  calculations
• Content?????
• Necessary but irrelevant

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The Tea Problem

• Doctor
• I am having an argument of an academic nature
  with one of my colleagues who was heating her tea
  water in the sissy tea pot in our office
  kitchen.  I told her to quit being such a wimp
  and heat her tea water in the microwave like a
  real man would do.  Her response was to the
  effect that water heated in the tea pot stayed
  hot longer than water heated to the same
  temperature in a microwave.  I don't believe it. 
  My position is that once removed from the heat
  source, the speed by which water cools is
  independent of the original source of heat.  We
  need professional help to resolve this.  Your
  thoughts please, at your convenience.

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The scientist answers

• At the risk of sounding diplomatic, always looked
  down upon in scientific circles, let me allege
  that you may both be correct.1.  You are
  absolutely right.  Once removed from the source
  of heat, it is absolutely irrelevant how the
  water was heated.  Water has a notoriously bad
  memory, inferior even to forty-something male
  professionals in a variety of disciplines.  The
  rate at which it cools depends only on the
  temperature of the water, and, 2. the vessel in
  which it finds itself.  Consider for example,
  what would happen if you poured 110 degree water
  into identical mugs, one of which was at an
  initial temperature of 40 degrees and the other
  at 120 degrees.  After three minutes, which water
  would be hotter?

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And

• Microwaves are especially efficient at heating
  water.  When removed from the oven, the water
  will likely be slightly hotter than its
  container, thus cooling a little faster.  While
  in a teapot, the water is heated by thermal
  contact with the pot itself, the pot would be
  slightly hotter than the water and the water
  would cool a little slower once the source of
  heat is removed.Finally, if the water is
  removed from the teapot and placed into a cold
  cup, it would cool fastest of all since this cold
  cup would absorb some of the heat from the
  water.Another thought -- water heated in a
  wussy teapot is often heated to a boil -- that's
  when the kettle sings.  Water heated in the
  microwave is usually removed prior to boiling,
  thus it begins at a lower temperature.Why isn't
  she drinking coffee like real people? 

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Student response
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And
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The Bottle Rocket Problem
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Student Response

• Research
• Calculations
• Experimentation
• Presentation to introductory class
• Myth Busters episode

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The Aluminum Helmet Problem

• See http//people.csail.mit.edu/rahimi/helmet/

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So, what did we cover?

• Mechanics (the bottle rocket problem)
• Thermodynamics (the tea problem)
• Electricity and Magnetism and Waves (the aluminum
  helmet problem)

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Sources for Ideas

• Myth Busters
• Urban legends references such as snopes.com
• Inquiries of friends
• The Physics Teacher
• The news