I am having a promlem figuring the acceleration: Figure shows a block of mass m resting on a 20 degree slope. The block has coefficients of friction mu_s =0.80 and mu_k =0.50 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have? My equation I have is: T-f_k-(mg*sin(theta))=m*a where f_k=u_k*(mg*cos(theta)) I keep getting the answer wrong. Is it my formula?