1. The problem statement, all variables and given/known data A small 700-g collar C can slide on a semicircular rod which is made to rotate about the vertical AB at a constant rate of 7.5 rad/s. The coefficients of friction are μs = 0.25 and μk = 0.20. Determine the magnitude of the friction force exerted on the collar immediately after release in the position corresponding to θ = 75 degrees. Pic attached below 2. Relevant equations F = ma an = d^2r/dt^2 - r(dθ/dt)^2 3. The attempt at a solution I began by determining net acceleration. a = (0.5 m)(7.5 rad/s)^2 = 28.125 m/s^2 pointed towards the center of the circle. So the net force is going to equal (0.7 kg)(28.125 m/s^2) = 19.6875 N towards the center of the circle. But I'm not sure what the FBD would look like in this case. I know that it'll have weight vertically down, but I am not sure how to set up the normal and frictional forces in this instance.