A solid sphere of radius 40.0 cm has a total positive charge of 30.0 µC uniformly distributed throughout its volume. Calculate the magnitude of the electric field:
(a) 0 cm from the center of the sphere kN/C
(b) 10.0 cm from the center of the sphere kN/C
(c) 40.0 cm from the center of the sphere kN/C
(d) 60.0 cm from the center of the sphere kN/C