J 4. Fig. 2 shows a thin plastic rod of length L = 12.0 cm and uniform positive charge (1 = 56.1 g; lying on an ixis. With V = 0 at infinity, find the electric potential at point P1 on the axis, at distance d = 2.50 cm from the rod. Remark: 1 fg(femtoCoulomb) = 1 x 10'15 C) Answer:l