Physics 308 Homework
 RU Links   Radford University   Department of Physics   RU Planetarium   RUSMART pages (weather) Spring 2014 Classes & Info   PHYS 308   PHYS 309   PHYS 450   My daily schedule   My C.V. Summer jobs/internships   NSF REU Program (list of REU sites) Other links   The Nucleus (resources for    physics/astronomy undergrads)   Pre-Health information   R.U.F.R.E.E.Z.I.N.G.    pics from the north pole trip    the picture from the trip   Simple 2-liter water rocket   American Institute of Physics Homework #9: Do not turn this in since the third test is Friday, April 4. I will post the solutions so that you can check your work. A (-)3.0μC charge is located at the point (x,y)=(10cm,(-)7.0cm). It is located next to the corner of a grounded box so that anything where y≥0 and anything where x≤0 is grounded. Find the potential at the point (x, y)=(2.0cm, -5.0cm). Consider a 45o "grounded wedge" in a cunductor. One side is along the positive x-axis (pointing to the right); the other starts at the origin, and is tiled at a 45o angle above the positive x-axis. Everywhere outside of this wedge is grounded. A (+)5.0μC charge is located at the point (x,y)=(10cm, 4.142cm)=(10cm,10cm*tan(22.5o)--this puts the charge 22.5o above the x-axis. Draw this situation, and carefully place the correct image charges on your drawing that would allow you to calculated the potential everywhere within that wedge. You do not need to calculate anything. problem 6.31. Be careful of your directions here. problem 6.50. Note that this combines the fields of two long straight wires, plus a half-circle. The integral limits of the long straight wires are simply from (-)∞ to 0 (lower wire) and from 0 to (-)∞ (upper wire). problem 6.52. Set it up and do the integrals, again thinking carefully about your integral limits. Note how these Biot-Savart problems require you to carefully set up the two vectors invovled in that relation. You should be able to set these up for almost any geometry, not just the specific ones in this homework.    That's all for homework #9.