Halliday, Resnick & Walker — Force and Motion–I: Problem 76

Figure 5.46 shows the cable rigging for a crane to lift a large container with mass \( 2.80 \times 10^4 \text{ kg} \) onto or from a ship. Assume that the mass is uniformly spread within the container. The container is supported at its corners by four identical cables that are under tension \( T_4 \) and that are at an angle \( \theta_4 = 60.0^\circ \) with the vertical. They are attached to a horizontal bar that is supported by two identical cables under tension \( T_2 \) and at angle \( \theta_2 = 40.0^\circ \) with the vertical. They are attached to the main crane cable that is under tension \( T_1 \) and vertical. Assume the mass of the bar is negligible compared to the weight of the container. What are the values of (a) \( T_1 \), (b) \( T_2 \), and (c) \( T_4 \)?