A charge of #-2 C# is at #(4, 7)# and a charge of #-1 C# is at #( 5, 2)#. If both coordinates are in meters, what is the force between the charges?

1 Answer
Jun 24, 2018

Charge #q_1=-2C# is placed at #(4,7)#
Charge #q_2=-1C# is placed at #(5,2)#

Distance between both charges is
#r=sqrt((5-4)^2+(2-7)^2#
#r=sqrt((1)^2+(-5)^2#
#r=sqrt(1+25#
#r=sqrt(26) m# and #r^2=26#

Force between two charges #q_1# and #q_2# is
#F=(kq_1q_2)/r^2 # where #k=9*10^9 Nm^2/C^2#
#=>F=((9*10^9)(-2)(-1))/(26#
#=>F=((9*10^9)(2))/(26#
#=>F=((9*10^9))/(13) N#
#=>F=0.6923*10^9 N#
or
#=>F=6.923*10^8 N#