A conducting spherical shell of inner radius a= 50.0 cm and outer radius b= 60.0 cm has a net charge Q1= -7.00 μC. A second larger conducting shell of inner radius c= 70.0 cm and outer radius d= 80.0cm has a net charge of Q2= +3.00 μC, and it is concentric with the first shell as shown in the figure to the left. What is the magnitude and direction of the electric field as a function of distance from the center of the spherical shells?