(Solved): Potential Energy due to niform Electric Field Consider the 1D motion of a charge q>0 along with ...
Potential Energy due to Úniform Electric Field Consider the 1D motion of a charge
q>0along with the vertically down uniform electric field
E=-|E|<0generated by a pair of charged parallel plates. Choosing up as the positive direction, let
h_(+)be the height of the positively charged plate and
h_(-)be the negatively charged plate such that
h_(+)>h_(-). For the time being, we ignore gravity. (a) Let
hbe in
h_(-)<=h<=h_(+). At the height
h, draw a free-body diagram. (b) The direction of the electrostatic force is downward. Let us define the distance traveled
d:=h_(-)-h_(+)<0, from
h_(+)to
h_(-). Calculate the total work
Wdone by electrostatic force force along with
d. (c) Choose a correct statement: 1)
W>0,2. (d) Find a relation among
K_(+-),W, applying the Work-Energy Theorem, where
K_(+-)stands for the kinetic energy of
qat
+--plate. (e) If it is under the uniform gravity
g=-|g|<0, as well as electric field
E, how do we modify the above result? Now, suppose the gravity is negligible. (f) The associated potential energy provides the work
W. If
U_(+-)are the potential energies at
h_(+-), i.e., at
+--plate, find a relation among
U_(+-),W. (g) If we choose the voltage of the lower plate
V_(0), relative to the earth, how much is the electric potential of the upper plate? Note that electric potential is the potential energy per unit charge.
