An infinitely long cylindrical shell is coaxial with the y axis and has a radius of 15 cm. It carries a uniform surface charge density σ = 6 μC/m2. A spherical shell of radius 25 cm is centered on the x axis at x = 50 cm and carries a uniform surface charge density σ = –12 μC/m2. Calculate the magnitude and direction of the electric field at

(a) The origin

(b) x = 20 cm, y = 10 cm; and

(c) x = 50 cm, y = 20 cm. (See Problem 42.)