A block of mass 4kg  is pressed against a wall by two perpendicular horizontal forces as shown in the figure. $F_1$ is perpendicular to the wall and $F_2$  is parallel to the wall. ${\mu }_s=0.8$ , ${\mu }_k=0.5$ and  $g=10\text{\hspace{0.17em}m}/{\text{s}}^{\text{2}}$

For $F_1=75\text{\hspace{0.17em}N}$ and  $F_2=30\text{\hspace{0.17em}N}$, the block remains at rest on the wall then the force of friction is