In a certain region of space, the electric field, E, is constant in direction (say horizontally in the +x-direction), but its magnitude decreases...

In a certain region of space, the electric field, E, is constant in direction (say horizontally in the +x-direction), but its magnitude decreases from E1 = 533.3 N/C at x = 0 to E2 = 415.3 N/C at x = 47.1 ( NOT at at x = 30 m as shown in Fig. 22-27). Determine the charge within a cubical box of side L = 47.1 m, where the box is oriented so that four of its sides are parallel to the E-field lines.