A telegraph pole OP has three wires connected to it at P. The other ends of the wires are connected to houses at A, B and C. Axes are set up as shown in Figure 4.27. The points relative to these axes, with distances in metres, are

The tension in each wire is 900 N. Find the total force acting at P. A tie cable at an angle of 45° is connected to P and fixed in the ground. Where should the ground fixing be placed, and what is the tension required to ensure a zero horizontal resultant force at P?

Figure 4.27