Final answer:
The tension in the cable and the force at the axle of a crane's boom can be calculated using the free-body diagram and static equilibrium conditions, taking into account the weight of the load and the boom.
Step-by-step explanation:
To calculate the tension in the cable and the force at the axle for a crane's boom lifting a load, it is essential to consider the forces and moments acting on the system. We start with the static equilibrium conditions which state that the sum of forces and moments for a body at rest must be zero.
Analysis for Tension (T)
Consider the boom AB with a 12.0-m length and a 3000-kg load at its end. Assuming gravity acts downward at 9.81 m/s², the force due to the load is F = m x g = 3000 kg x 9.81 m/s². The center of gravity of the boom, which weighs 1000 kg, is located in the middle at 6.0 m from point A. Thus its force is also F = m x g = 1000 kg x 9.81 m/s². For the system to be in equilibrium, the tension in the cable must balance out these forces.
Force at Axle A
To calculate the force at axle A, one must consider the torques around a pivot point, typically chosen at the point where the tension or the force at the axle is being calculated. By summing the moments around axle A and setting them equal to zero, you can solve for the unknowns. The force of the weight of the boom and the load creates a counterclockwise moment, while the tension creates a clockwise moment.
By using these principles and the appropriate free-body diagrams, the calculations will yield the values for the tension T in the cable and the force at the axle A.