Find the displacement current through a parallel-plate capacitor. Assume that V is the voltage across the capacitor at any instant. Express your answer in terms of the variables C and dV/dt.

displacement current; i_d = C(dV/dt)

Explanation:

Let i_d be the displacement current

Thus,

i_d = ε_o(dΦ/dt)

We know that flux Φ = EA

Thus,

i_d = ε_oA(dE/dt)

We also know that E = V/d

Thus, i_d = ε_oA(d(V/d)/dt)

i_d = ε_o(A/d)(dV/dt)

Now, capacitance has a formula of;

C = ε_o(A/d)

Thus,

i_d = C(dV/dt)

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.