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 1
 Problem Statement

Three long, straight, parallel wires all lie in the yz plane and each carries a current of 20
A in the positive z direction. The two outer wires are each 4.0 cm from the center wire.
What is the magnitude of the magnetic force on a 50cm length of either of the outer
wires?
answer is 1.5 mN
 Relevant Equations
 f12 (l) = (uo * i1* i2)/(2pi * r)
This is how I visualize the problem (of course I am drawing this as if it is in the zy axis); I don't know what will be the next step. Anyone please help me.
Thank you