Consider the two closely spaced points A and B.  The electric potential at 
points A and B are 500 and 400 Volts, respectively.
<ol type=a>
  <li>Calculate the potential energy a +2.0 C would have at both points A and B.
  <li>If the + 2.0 C  charge is placed at point A and released, will it move towards point B ?
  <li>Calculate the potential energy that a -0.5 C would have at points A and B ?
  <li>If the -0.5 C charge is placed at point A and released, will it move towards point B ?
</ol>