A parallel-plate capacitor is constructed of two horizontal 12.0-cm-diameter circular plates. A 1.1 g plastic bead with a charge of -5.6 nC is suspended between the two plates by the force of the electric field between them. What is the charge on the positive plate?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

How does the strength of the electrostatic force between an electron and a proton compare to the strength of the gravitational force between them?