Question

A closed surface is constructed in the space between two large parallel metal plates, where there is a constant electric field E. The magnitude of the field is |E| = 1880 N/C. The numbers (1), (2), and (3) in the simulation label small increments of area of 1.1 cm^2 on the surface. The direction of each increment is defined to be the direction of a vector out of the surface and perpendicular to the increment's surface area. With that definition assume the direction of the first increment ΔA1 is 65° from the direction of E, that the second increment ΔA2 is oriented 90° from the direction of E, and that the third increment ΔA3 is oriented 135° from the direction of E. Find the flux through each of the three increments of area

Answer 1

I use the formula Phi=EAcos(θ)
For ΔA1 I got 1880(.00011m^2)cos(65)=.05486N*m^2/C but this is not the answer. Can somebody show how to get to the answer key .0874N*m^2/C? Once I know how I will do the rest for the 2 and 3

Answer 2

angle wrong, 65 to normal is 25 to surface. zero would be flat against your hot plate 90 - 65 = 25
1880(.00011m^2)cos(25) = 0.1874 not 0.0874