
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 $\displaystyle F_n + F_f + F_w = 0$.
Thus, $\displaystyle F_n + F_f = F_w$.
Now, using coordinate system b, $\displaystyle F_w = <0, mg>$, where m is the mass of the block and g is the acceleration due to gravity. Also, you know that $\displaystyle F_n = <\lambda \sin \theta, \lambda \cos \theta>$, $\displaystyle F_f = <\omega \cos \theta, \omega \sin \theta>$, and $\displaystyle \lambda^2 + \omega^2 = (mg)^2$. Can you figure out how to solve for $\displaystyle \lambda$ and $\displaystyle \omega$?