PLC Activity #1
Coulomb’s Law
Due: see website for due date
How to get credit for this activity
First, sign-in into your attendance sheet and sign-out when the activity is complete. Show your
work and results to a PLC tutor so they can check your work and initial the signoff sheet. Be
prepared to answer questions about the activity or your results.
Question 1
The figure below shows four situations in which charged particles are fixed in place on an axis.
In which situations is there a point to the left of the particles where an electron will be in
equilibrium (i.e. the net force on it will be zero)?
Question 2
Given below are arrangements of three fixed electric charges. In each figure, a point labeled P
is also identified. All of the charges are the same size charge, q, but they can be either positive
or negative as indicated. The charges and point P all lie on a straight line. The distances
between adjacent items, either between two charges or between a charge and point P, are all
the same. There are no other charges in this region. A test charge, +Q, is placed at point P.
a. Rank these arrangements from greatest to least on the basis of the strength (magnitude) of
the electric force on the test charge, +Q, at P.
b. Please carefully explain your reasoning.