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

1 Answer
Mar 28, 2016

Answer:

#F_"net"=28.10^9" N"#

Explanation:

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#"The force between two charges is given by formula:"#

#F=k*(q_1*q_2)/r^2#

#r:"distance between two charges"#
#q_1:"the first charge"#
#q_2:"the second charge"#
#F_"AB":" represents the force between charges A and B"#
#F_"CB":"represents the force between charges C and B"#
#F_"AB" and F_"CB" " are opposite forces"#
#F_"AB"=k*((-4)*(-4))/2^2" "F_"AB"=(16*k)/4=4*k#

#F_"CB"=k*((-2)*(-4))/3^2=" "F_"AB"=(8k)/9#

#F_"net"=F_"AB"-F_"CB"#

#F_"net"=4*k-(8*k)/9#

#F_"net"=(36*k-8*k)/9#

#F_"net"=(28*k)/9" "k=9*10^9 #

#F_"net"=(28*cancel(9)*10^9)/cancel(9)#

#F_"net"=28.10^9" N"#