Meriam, Kraige & Bolton — Kinematics of Particles: Problem 2_112

2/112 The boom \(OAB\) pivots about point \(O\), while section \(AB\) simultaneously extends from within section \(OA\). Determine the velocity and acceleration of the center \(B\) of the pulley for the following conditions: \(\theta = 20^\circ\), \(\dot{\theta} = 5 \text{ deg/sec}\), \(\ddot{\theta} = 2 \text{ deg/sec}^2\), \(l = 7 \text{ ft}\), \(\dot{l} = 1.5 \text{ ft/sec}\), \(\ddot{l} = -4 \text{ ft/sec}^2\). The quantities \(\dot{l}\) and \(\ddot{l}\) are the first and second time derivatives, respectively, of the length \(l\) of section \(AB\).