Three force ${\mathrm{F}}_1=10\mathrm{N},{\mathrm{F}}_2=8\mathrm{N},{\mathrm{F}}_3=6\mathrm{N}$ are acting on a particle of mass 5kg. The forces ${\text{F}}_2$ and ${\text{F}}_3$ are applied perpendicularly so that particle remains at rest. If the force ${\text{F}}_1$ is removed, then the acceleration of the particle is: