put the +5 at x = 0 and the -3 at x = d
at some point beyond d the work done to pull a charge in from x = oo is zero, the +5 pulling one way and the -3 the other way. The potential is proportional to charge *1/distance
total work = c * 5/x - c *3/(x-d)
5/x = 3/(x-d)
5x-5d = 3 x
2 x = 5 d
d = 16 cm
so
x = (5/2)(16) = 40 cm
come closer and the -3 wins
go way far away and it looks like charge of +2 at zero :)
Two charges 5*10^-8 and -3*10^-8 C are located 16cm apart in air. At
what point on the line joining the two charges is the total electric potential zero? Take the potential at infinity to be zero
1 answer
1 answer