The 2-kg bar rotates in the horizontal plane about the smooth pin. The 6-kg collar A slide...

The 2-kg bar rotates in the horizontal plane about the smooth pin. The 6-kg collar A slides on the smooth bar. At the instant shown, r = 1.2 m, ω = 0.4 rad/s, and the collar is sliding outward at 0.5 m/s relative to the bar. If you neglect the moment of inertia of the collar (that is, treat the collar as a particle), what is the bar’s angular acceleration?

Strategy: Draw individual free-body diagrams of the bar and the collar, and write Newton’s second law for the collar in polar coordinates.