Two charges of # 7 C # and # 5 C# are positioned on a line at points # 2 # and # -4 #, respectively. What is the net force on a charge of # -4 C# at # 0 #?

1 Answer
Mar 6, 2016

Answer:

#=51.75*10^9N#

Explanation:

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By Coulomb's law we Know that force between two charges Q and q situated at a distance r is given by the formula #F=k(qQ)/r^2#,where k =Coulomb's constant=#9*10^9Nm^2C^-2#

Applying this formula the attractive force of 7C on -4C
=#9*10^9*4*7/2^2N=63*10^9N#
The attractive force of 5C on -4C =#9*10^9*4*5/4^2N=11.25*10^9N#

These two forces are oppositely directed so the net force will be towards right and its magnitude #=(63-11.25)*10^9N=51.75*10^9N#