ADDITIONS TO Y&F PROBLEMS AND PROBLEMS FROM OTHER TEXTS
                               
                              JULY 2 - JULY 10
        
         (P prefixes) HRW Problem Supplement #1 - CHAPTER 22
         26.  Calculate the number of coulombs of positive charge
              in 250 cm^3 of (neutral) water (about a glassful).

         WOLFSON - CHAPTER 23
         16.  A charge 3q is at the origin, and a charge -2q is on
              the positive x axis at x = a.  Where would you place
              a third charge so it would experience no net electric
              force?
         
         32.  A 1.0 microC charge and a 2.0 microC charge are 10 cm
              apart.  (a) Find a point where the net electric field 
              is zero.  (b) Sketch the net electric field lines 
              qualitatively.


         (P prefixes) HRW Problem Supplement #1 - CHAPTER 23
         25.  A semi-infinite nonconducting rod (i.e. infinite in one
              direction only) has uniform positive linear charge density 
              lambda.  Show that the electric field at point P makes an 
              angle of 45 degrees with the rod and that this result is
              independent of the distance R.  (HINT: Separately find 
              the parallel and perpendicular (to the rod) components
              of the electric field at P, and then compare those 
              components.)

                 rod
                starts
                 here
               _   +++++++++++++++++++++++++ =====> very long
               |  |
                  |
               R  |
                  |
               |  |
               -  P  <== this point is a distance R from the end
                         of the rod

         37.  In Millikan's experiment, an oil drop of radius 
              1.64 microns and density 0.851 g/cm^3 is suspended in
              the experimental chamber when a downward-directed
              electric field of 1.92 X 10^5 N/C is applied.  Find
              the charge on the drop, in terms of e.

         55.  A charge (uniform linear density = 9.0 nC/m) lies on a 
              string that is stretched along an x axis from x = 0 to 
              x = 3.0 m.  Determine the magnitude of the electric 
              field at x = 4.0 m on the x axis.

         59.  An electric dipole swings from an initial orientation i 
              to a final orientation f in a uniform external electric 
              field E.  E points in the +y direction, in orientation i 
              the dipole points 20 degrees below the -x direction, and 
              in orientation f the dipole points 20 degrees above the 
              -x direction.  The electric dipole moment is 1.60 x 
              10^{-27} Cm; the field magnitude is 3.00 x 10^6 N/C.  
              What is the change in the dipole's potential energy?

         (P prefixes) HRW Problem Supplement #1 - CHAPTER 24
         24.  A charge of uniform linear density 2.0 nC/m is distributed
              along a long, thin, nonconducting rod.  The rod is coaxial
              with a long, hollow, conducting cylinder (inner radius =
              5.0 cm, outer radius = 10 cm).  The net charge on the
              conductor is zero.  (a) What is the magnitude of the
              electric field 15 cm from the axis of the cylinder?  What
              is the surface charge density on (b) the inner surface and 
              (c) the outer surface of the conductor?


         FISHBANE PROBLEMS - CHAPTER 24
         38.  Two large, thin, metallic plates are placed parallel to 
              each other, separated by 15 cm.  The top plate carries a 
              uniform charge density of 24 microC/m^2, while the bottom 
              plate carries a uniform charge density of -38 microC/m^2.  
              What is the electric field (magnitude and direction) (a) 
              halfway between the plates? (b) above the two plates?  
              (c) below the two plates? (d)  What are the surface charge 
              densities on the top and bottom surfaces of both plates?

         45.  A metal sphere of radius a is surrounded by a metal shell 
              of inner radius b and outer radius R.  The flux through a 
              spherical Gaussian surface located between a and b is 
              Q/epsilon0, and the flux through a spherical Gaussian 
              surface just outside radius R is 2Q/epsilon0.  (a) What 
              are the total charges on the inner sphere and on the shell?  
              (b) Where are the charges located, and (c) what are the 
              charge densities?

         Halliday and Resnick - 2nd Edition - CHAPTER 25
          1.  Water in an irrigation ditch of width w = 3.22 m and
              depth d = 1.04 m flows with a speed of 0.207 m/s.  The
              mass flux of the flowing water through an imaginary
              surface is the product of the water's density (1000 kg/m^3)
              and its volume flux through that surface.  Find the mass
              flux through the following imaginary surfaces:  (a) a
              surface of area wd, entirely in the water, perpendicular
              to the flow;  (b) a surface with area 3wd/2, of which wd
              is in the water, perpendicular to the flow;  (c) a surface
              of area wd/2, entirely in the water, perpendicular to the 
              flow;  (d) a surface of area wd, half in the water and 
              half out, perpendicular to the flow;  (e) a surface of
              area wd, entirely in the water, with its normal 34 degrees
              from the direction of flow.

         (P prefixes) HRW Problem Supplement #1 - CHAPTER 25
         88.  Three particles with the same charge q and same mass m are 
              initially fixed in place to form an equilateral triangle 
              with edge lengths d.  (a) If the particles are released 
              simultaneously, what are their speeds when they have 
              traveled a large distance (effectively an infinite distance)
              from each other?  (Measure the speeds in the original rest 
              frame of the particles.)

              Suppose, instead, the particles are released one at a time:  
              The first one is released, and then, when the first one is 
              at a large distance, a second one is released, and then, when 
              that second one is at a large distance, the last one is
              released.  What then are the final speeds of (b) the first 
              particle, (c) the second particle, and (d) the last particle?

         WOLFSON - CHAPTER 26
          3.  Four 50 microC charges are brought from far apart onto a
              line where they are spaced at 2.0 cm intervals.  How much
              work does it take to assemble this charge distribution?