Side of t he cube is 2m finel tha net f throughthe Surfoce o

Side of t he cube is 2m, finel tha net f through-the Surfoce of the cube 25NC 135 2 20

dA = 2*2 = 4 m^2

Flux through the side faces:

phix = integral(Ex.dA) = E1x*dA*cos 0 + E2x*dA*cos 180 = 35*2*2*1 + 20*2*2*(-1) = 60 N.m^2/C

flux through up and down face:

phiy = integral(Ey.dA) = E1y*dA*cos 0 + E2y*dA*cos 180 = 25*2*2*1 + 15*2*2*(-1) = 40 N.m^2/C

flux through front and back face:

phiz = integral(Ez.dA) = E1z*dA*cos 0 + E2z*dA*cos 180 = 20*2*2*1 + 20*2*2*(-1) = 0 N.m^2/C

Net flux through cube is:

phi = phix + phiy + phiz = 60 + 40 + 0 = 100 N.m^2/C

Let me know if you have any doubt.