A uniformly charged disk has radius R=3 cm and surface charge density o=4 C/m?. Calculate the electric potential at a point x=3 cm along the perpendicular central axis of the disk. (Your result must be in multiples of 107 Volts. That means if, for example, you get a result of 9.22 x 10' just type 9.22 in the answer box. Include 1 digit after the decimal point and maximum of 2% of error is accepted in your answer. Take k=9x10.) R Vr+x dA 2wr dr dr