Write an expression for the magnitude of the normal force, fn, acting on the block, in terms of f2 and the other variables of the problem. assume that the surface it rests on is rigid.

If the force is fn, then it acting on the block, in the term of f2 and the other variables of the problems. then we assume the surface is rest on it's rigid, then the magnitude of the force is, fn = f2 sin (?) + m g