Incline plane and static friction

[linnus]

Homework Statement

A block sits on an inclined plane, which is slowly being raised. The block remains motionless until the angle the plane makes with the horizontal is 23°. At this angle, the block begins to slide down the plane. What is the coefficient of static friction between the plane and the block?

Homework Equations

F(static friction)= u(s) Fn
mgsin(23)= x component
mgcos (23)= y component
F=ma

The Attempt at a Solution

I don't know where to even start since it doesn't give me a mass or weight...

 

[Vijay Bhatnagar]

This angle at which the block just starts to slide is called sliding angle. What is the relation between the tangent of sliding angle and coefficient of static friction?

 

[linnus]

coefficient of static friction=tan (x)
oh..so the answer is tan (23)=.4244
Thanks!