Final answer:
The problem involves calculating the compression of the pole, its bending, and the tension in a guy wire necessary to keep it straight, using principles of physics. Specific numerical calculations cannot be provided without detailed information such as the actual tension in the power lines and the dimensions and properties of the pole. The principle involves applying statics, mechanics, and trigonometry.
Step-by-step explanation:
To address the problem of a telephone pole at a 90° bend in a power line being subjected to shear forces, we need to use principles of mechanics and statics. Specific calculations are required to find (a) the compression of the pole due to the load it experiences, (b) the extent of the bending and the direction it bends towards, and (c) the tension required in a guy wire to counteract this bending and keep the pole straight when attached at a 30° angle with the vertical.
For such calculations, we would typically consider variables such as the tension in the power lines, the dimensions and material properties of the pole, and any angles given that relate to how guy wires are attached to the pole. However, since the actual details required for these calculations, such as the tension in the power lines at the angles shown, are not provided in the student's question, we cannot provide specific numerical answers. The student may need to reference the textbook or other resources for the missing details to complete their calculations.
Nevertheless, it's important to note that finding the compression of the pole would involve assessing the forces acting on it and how these forces cause deformation, which may involve calculations using Hooke's Law for the compression of materials. Determining how the pole bends would involve an analysis of the moments and forces at play, whereas calculating the tension in the guy wire would apply the principles of trigonometry, specifically resolving forces in the direction orthogonal to the pole to ensure it remains vertical.