Two charges of # 6 C # and # -7 C# are positioned on a line at points # -7 # and # 8 #, respectively. What is the net force on a charge of # -3 C# at # 2 #?

1 Answer
Nov 25, 2017

Answer:

#0.361# Relative net repulsive force from right to left.

Explanation:

#6C_(-7) .........-3C_(2).......-7C_(8)#

Coulomb's Law states:

#F = k_e (q_1q_2)/r^2#

Coulomb's Constant #k_e = 8.99×10^9 N m^2 C^(−2)#

Without specifying the distance units we can take the relative value without the constant. Distance_1 = 2 - (-7) = 9, Distance_2 = 8 - 2 = 6

#F_(1-2) = (q_1q_2)/r^2 = (6)(-3)/9^2 = -0.222# (attractive)

#F_(2-3) = (q_2q_3)/r^2 = (-3)(-7)/6^2 = 0.583# (repulsive)

#F_(net) = -0.222 + 0.583 = 0.361# Net repulsive from right to left.