Charges q1 and q2 lie on the x-axis at points x= -a and x= +a respectively a) how must must q1 and q2 be related for the net force +Q placed at x= +a/2 to be zero?

Question

Charges q1 and q2 lie on the x-axis at points x= -a and x= +a respectively a) how must must q1 and q2  be related for the net force +Q placed at x= +a/2  to be zero?

bobpursley · Accepted Answer

zero, then the forces are equal and opposite. q1*q/(3a/2)^2=q2*q/(a/2)^2 q1=9 q2 another way to look at this is q1 is 3 times the distance from q as is q2