Two charges of # -1 C # and # -3 C# are positioned on a line at points # -2 # and # 12 #, respectively. What is the net force on a charge of # 4 C# at # -1 #?

1 Answer
Apr 30, 2017

#vecF_(BD)=35.361*10^9 N#

Explanation:

enter image source here
Upon seeing the Diagram we first focus on the FBD for the charge at D .
general formula used here is
#F=1/(4piepsilon_o)*(q_1*q_2)/r^2#

#:.# #F_(DB)=9*10^9*(-1*4)/(1)^2=-36*10^9N#
Which is attractive force due negative x-axis direction .

#F_(DC)=9*10^9*(-3*4)/(13)^2=-0.639*10^9#
hence , # vecF_(DB)>vecF_(DC)#

so the direction is towards #vecF_(DB)#
hence the net force is in the direction of #vecF_(BD)=35.361*10^9 N#