Question

It is found experimentally that the electric field in a certain region of Earth's atmosphere is directed vertically down. At a certain location, at an altitude of 508 m the electric field has magnitude 19.6 N/C and at an altitude of 780 m the magnitude is 76.0 N/C. Find the net amount of charge contained in a cube with horizontal faces at altitudes of 508 and 780 m. Neglect the curvature of Earth.

Give answer in the form of "+/-a.bc x 10^(x) C".

preparing for a test

Answer 1

It is found experimentally that the electric field in a certainregion of Earth's atmosphere is directed vertically down. At analtitude of 260 m the field hasmagnitude 60.0 N/C. At an altitude of 190 m, the magnitude is 100 N/C. Find the netamount of charge contained in a cube 70 m on edge, with horizontal faces at altitudesof 190 and 260 m. Neglect the curvature of Earth.

quetion is similar just cahnge the values

Given that at y- 260m, E-60 NIC Aty 190m, E-100j NC Note that only horizontal faces contribute to the total flux For all other faces, d is perpendicular to E. Therefore, Flux through the cube φ EA ,fes +EA face 0. E. A -60j (70) --294000 Nm2/C E.A 100%(70 -490000 Nm C face={- - Now, using equation () 294000+490000 196000 NmC If net charge in the cube, Then -8.85x10-2 x 196000 11 7.34x10"C