
Physics Help!
I need help with the current problem
Because the block is not moving, the sum of the y components of the forces acting on the block must be zero. Find an expression for the sum of the y components of the forces acting on the block, using coordinate system b.
Express your answer in terms of some or all of the variables http://session.masteringphysics.com/render?var=F_n, http://session.masteringphysics.com/render?var=F_f, http://session.masteringphysics.com/render?var=F_w, and http://session.masteringphysics.com/render?var=theta.
http://i86.photobucket.com/albums/k1...s/MFS_1l_1.jpg
Thanks!

Because the sum of the forces on the block is zero, you must have .
Thus, .
Now, using coordinate system b, , where m is the mass of the block and g is the acceleration due to gravity. Also, you know that , , and . Can you figure out how to solve for and ?