8 (a) An object can be both charged and polarized. On a negatively charged metal ball, the charge is spread uniformly all over the surface (Figure 14.42). If a positive charge is brought near, the charged ball will polarize. If any of the following quantities is zero, state this explicitly. (1) Draw the approximate final charge distribution on the ball. (2) At the center, draw the electric field due to the external positive charge. (3) At the center, draw the electric field due to the charge on the surface of the ball. (4) At the center, draw the net electric field.
(b) Next, consider a negatively charged plastic pen that is brought near a neutral solid metal cylinder (Figure 14.43). If any of the following quantities is zero, state this explicitly. (1) Show the approximate charge distribution for the metal cylinder. (2) Draw a vector representing the net force exerted by the pen on the metal cylinder, and explain your force vector briefly but completely, including all relevant interactions. (3) At the center, draw the electric field due to the external negative charge. (4) At the center, draw the electric field due to the charge on the surface of the ball. (5) At the center, draw the net electric field.
(c) Replace the solid metal cylinder with a solid plastic cylinder. (1) Show the approximate charge distribution for the plastic cylinder. (2) Draw a vector representing the net force exerted by the pen on the plastic cylinder. (3) Explain your force vector briefly but completely, including all relevant interactions.
