The question should really give you more information. Is mu the coefficient of static or kinetic friction? What is [itex]F_{1}[/itex]? I'm assuming [itex]F_{2}[/itex] is the applied force, and [itex]F_{1}[/itex] is the net force. Maybe they want you to find the frictional force? Seriously, this is the worst-written question I've ever seen. Are you sure you included everthing? The way it is, there is no unknown variable. Oh boy...
What specifically are you trying to solve. The net force on the object?
If so a good place to start would be to separate your horizontal and vertical forces. Don't forget that you can convert F2 into horizontal and vertical components aswell.
Don't forget Newton's Second Law. The frictional force can be found using the normal force (all required information is given) and the coefficient of friction.
Then you should have everything you need to complete the problem and find the net force acting on the mass.
I rushed through the problem and I didn't have a calculator on hand but I believe the solution should come out to approximately 15N [R].