I have a question about calculating (omega_f)^2. Should we
use the vAve we calculated for horizontal motion, the final
velocity we calculated for vertical motion, or do we need to
use 1/2 mvf^2 = KEf (like you did in class today)? I was
not sure which velocity v/r referred to.
When the ball is moving with velocity v the value of omega is v / R.
Since you are calculating the change in KE from start to leaving the ramp, you need to use the velocity as the ball leaves the ramp.
The situation is not a uniform-acceleration situation, since the acceleration changes when the ball moves leaves the inclined ramp and encouters the horizontal ramp. (Acceleration changes once more when the ball leaves the horizontal ramp, but that's after the desired velocity has been reached).