{{page>wiki:headers:hheader}} Navigate [[..:..:..:activities:link|back to the activity]]. COMMENTARY From Stephanie Chasteen, University of Colorado - Boulder We used this activity as the basis for an upper-division (junior-level) tutorial in E&M at our university. We found a surprising amount of student difficulty in setting up the integral to find E from a ring of charge, especially in setting up Griffiths' "script-r". We used an amended version of OSU's "Star Trek" activity in order to discuss script-r. Students were not comfortable with this notation or the direction of script-r, and the tutorial was valuable. There was some difficulty in translating from cartesian to cylindrical or spherical coordinates. After practice in using script-r in one part of the tutorial, they continued to have difficulty in extending this understanding to a new situation. In doing the actual integral, many students were confused about how to integrate over a vector (are there one integral or three?). Our tutorial, plus detailed comments, are attached. * Tutorial 1 - Charged bike tire{{talk:activities:3310_tutorial_final.pdf|}} * Tutorial 1 - Instructor's handbook{{talk:activities:3310_tutorial1_manual_final.pdf|}}