Carl Mungan

• Many people (myself included) are interested in the physics of potato guns. Mark Denny has a very accessible analysis of how the muzzle speed and mechanical efficiency depend on the barrel length in the February 2011 issue of The Physics Teacher. I also enjoyed thinking about the “Direction of Friction” for a cylinder rolling without slipping up and down an incline in Paul Hewitt’s January 2011 Figuring Physics column. Finally, if you teach thermodynamics, you may wish to consider Todd Timberlake’s suggested coin-flipping activities on page 516 of the November 2010 issue.
  
  
• The February 2011 issue of the American Journal of Physics has an article beginning on page 193 that compares theory and experiment for some extensions of the familiar demonstration of dropping a magnet down a conducting pipe: What happens if you drop two magnets? How does the magnetic braking force depend on the distance between the magnet and the pipe wall? In the January 2011 issue, the article “Listening to student conversations during clicker questions” gave me some interesting new ideas to help me improve my use of student response systems in introductory physics.
  
  
• I enjoyed the various tidbits in the End Results section of the January 2011 issue of Physics Education. Also, the old chestnut of whether one should walk or run in the rain to minimize how wet one gets is discussed on page 355 of the March 2011 issue of the European Journal of Physics. Both journals can be accessed at http://iopscience.iop.org/journals.
  
  
• The 1 January 2011 issue of the Journal of Chemical Education discusses the issue of dimensional analysis involving transcendental functions (such as sine or logarithm) on page 67.
  
  
• I was intrigued by the discussion of how a fly can walk upside down on a ceiling without falling off in the online version of Physics World. Apparently the secret involves an emulsion of two different fluids secreted by a fly’s feet.
  
  
• APS recently highlighted an article in Physical Review Letters about a state-of-the-art determination of the Avogadro constant at http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.030801. I find it to be an interesting exercise to brainstorm with students various ideas for how one might determine the values of such constants.

---

Disclaimer - The articles and opinion pieces found in this issue of the APS Forum on Education Newsletter are not peer refereed and represent solely the views of the authors and not necessarily the views of the APS.