A truss analysis includes consideration of Joint A as shown. If P is $5\mathrm{.}9$ kN and Q is $3\mathrm{.}9$ kN $,$ find member force $\backslash ($ A B $\backslash )$ in kN $.$ Use positive for tension and negative for compression. The horizontal distance from $\backslash ($ A $\backslash )$ to $\backslash ($ B $\backslash )$ is $6$ m $,$ the horizontal distance from A to C is $4$ m $,$ and the vertical distance from $\backslash ($ A $\backslash )$ to both $\backslash ($ B $\backslash )$ and $\backslash ($ C $\backslash )$ is $5$ m $.$