Two charges of # -3 C # and # -1 C# are positioned on a line at points # -1 # and # 4 #, respectively. What is the net force on a charge of # 1 C# at # 2 #?

1 Answer
Jan 27, 2016

#F = 9.0 xx 10^9 (3)/25 = 7.2 xx10^8 N#

Explanation:

The force between 2 charged particles is

#F = K (q_1 q_2)/r^2 # where
#q_i = "Charges of the particles", K = 9.0 xx 10^9 N*m^2/C^2 #
Inserting the value of #q_1 = -3; q_2 = -1; r = (4- (-1)) = 5 #
#F = 9.0 xx 10^9 (3)/25 = 7.2 xx10^8 N#
Note: The force between 1 coulomb charges separated by 5 meters is huge - roughly about a billion Newtons. What does this tell you?
Well the unit of Coulomb is pretty large, and for that size 5 meters separation generated and amazing (unrealistic amount of force)