Two long, parallel wires separated by

$2\mathrm{.}05$ cm

carry currents in opposite directions. The current in one wire is

$1\mathrm{.}30$ A

$,$ and the current in the other is

$3\mathrm{.}10$ A

$.($a$)$ Find the magnitude of the force per unit length that one wire exerts on the other.

N$/$m

$($b$)$ Is the force attractive or repulsive? attractive repulsive