$3$ Friction on Wall $[6$Points$]$

A block of mass m$=3$kg is being pushed towards a wall with a force of magnitude F$=25$N at an angle theta$=60$ with the horizontal, as shown in the figure. The static friction coefficient between the block and the wall amounts to mu$\_($s$)=0\mathrm{.}8.$

a$)$ Draw a free body diagram indicating all forces acting on the block and, if necessary, their relevant components. Choose a meaningful coordinate system.

b$)$ What is the magnitude of the maximal possible static friction force?

c$)$ Is force F strong enough, to prevent the block from sliding down

the wall?

d$)$ Find the angle, at which the force F applied to prevent the block

from sliding, is minimal.