Electric potential is expressed as:
, where ke is Coulomb's constant, q is a charge, and r is the distance from the point of the potential to the charge.
Let's take point i to be at distance, r = d, and point f to be at distance, r = 3d from the fixed charge.
Initial electric potential,
Final electric potential,
A. Suppose we have a positive charge fixed in place. What net change in electric potential will we see if we move from the point I to point f, positive, negative or zero? (Just the net difference; you don’t have to describe what happens during the move). Explain your answer using V = keq/r
B. What is the electric potential energy of the following pair of charges?
qA = 4.00 x 10-7 C
qB = 2.00 x 10-6 C
rAB = 3.00 x 10-5 m
ke = 8.99x109 Nm2/C2
C. If we were to place a negative charge in between the two positive charges in part B would the change in the total electric potential energy be positive, negative or zero? Explain using PEE = keq1q2/r12
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