A solid conducting sphere of radius 5. 00 cmcm carries a net charge. To find the value of the charge, you measure the potential difference vab=va−vbvab=va−vb between point aa, which is 8. 00 cmcm from the center of the sphere, and point bb, which is a distance rr from the center of the sphere. You repeat these measurements for several values of r>8cmr>8cm. When you plot your data as vabvab versus 1/r1/r, the values lie close to a straight line with slope -18. 0 v⋅mv⋅m