Here, $m=5\,\text{kg}, \vec{a}=?$$\vec{F}_1=\overline{OA}=8\,\text{N} ; \vec{F}_2=\overline{OB}=6\,\text{N}$Resultant force, $\vec{F}=\overline{OC}$ $= \sqrt{F_{1}^{2}+F_{2}^{2}}$ $= \sqrt{8^{2}+6^{2}} = 10\,\text{N}$ Therefore magnitude of the acceleration produced$a= \frac{F}{m}= \frac{10}{5}=2\,\text{m}\,\text{s}^{-2}$This is the direction of resultant force and hence the direction of acceleration of the body.