Chapter 11, Problem 80GP

A radio transmission tower has a mass of 80 kg and is 12 m high. The tower is anchored to the ground by a flexible joint at its base, but it is secured by three cables 120° apart (Fig. 11–50). In an analysis of a potential failure, a mechanical engineer needs to determine the behavior of the tower if one of the cables broke. The tower would fall away from the broken cable, rotating about its base. Determine the speed of the top of the tower as a function of the rotation angle θ. Start your analysis with the rotational dynamics equation of motion $d\stackrel{\to }{L}/dt={\stackrel{\to }{\tau }}_{\text{net}}$. Approximate the tower as a tall thin rod.

FIGURE 11–50 Problem 80.