Final answer:
The potential near the surface of the plastic sphere is 1.44 V.
Step-by-step explanation:
The electric potential near the surface of a charged sphere can be calculated using the formula V = k * Q / r, where V is the potential, k is the Coulomb's constant (9 * 10^9 Nm^2/C^2), Q is the charge, and r is the distance from the center of the sphere.
In this case, the diameter of the sphere is 0.500 cm, which means the radius is 0.250 cm or 0.0025 m. The charge on the surface is 40.0 pC or 40.0 * 10^-12 C. Plugging in these values into the formula, we get V = (9 * 10^9 Nm^2/C^2) * (40.0 * 10^-12 C) / (0.0025 m) = 1.44 V. Therefore, the potential near the surface of the sphere is approximately 1.44 V.